Rename exec_tools to tools

Follow up to #43156
Based on
https://github.com/bazelbuild/bazel/issues/12059#issuecomment-725641997
exec_tools might no longer be needed and hence can be replaced by tools.
This fixes various build failures caused by missing environment
variables in environments where they are required, e.g. using custom
compilers.
diff --git a/tensorflow/compiler/aot/tests/BUILD b/tensorflow/compiler/aot/tests/BUILD
index 06745de..51298a4 100644
--- a/tensorflow/compiler/aot/tests/BUILD
+++ b/tensorflow/compiler/aot/tests/BUILD
@@ -115,7 +115,7 @@
     # have control of the full GPU.
     cmd = "CUDA_VISIBLE_DEVICES='' " +
           "$(location :make_test_graphs) --out_dir $(@D)",
-    exec_tools = [":make_test_graphs"],
+    tools = [":make_test_graphs"],
     tags = ["manual"],
 )
 
diff --git a/tensorflow/compiler/aot/tfcompile.bzl b/tensorflow/compiler/aot/tfcompile.bzl
index 742cb30..29f37bf 100644
--- a/tensorflow/compiler/aot/tfcompile.bzl
+++ b/tensorflow/compiler/aot/tfcompile.bzl
@@ -127,7 +127,7 @@
                    "$(location " + tfcompile_tool + ")" +
                    " --config=$(location " + config + ")" +
                    " --dump_fetch_nodes > $@"),
-            exec_tools = [tfcompile_tool],
+            tools = [tfcompile_tool],
             # Run tfcompile on the build host, rather than forge, since it's
             # typically way faster on the local machine.
             local = 1,
@@ -162,7 +162,7 @@
                 "//tensorflow/python/tools:freeze_graph)" +
                 freeze_args
             ),
-            exec_tools = ["//tensorflow/python/tools:freeze_graph"],
+            tools = ["//tensorflow/python/tools:freeze_graph"],
             tags = tags,
         )
         tfcompile_graph = freeze_file
@@ -242,7 +242,7 @@
             " --out_function_object=$(@D)/" + function_object_file +
             " " + flags + " " + profiling_flag + " " + mlir_flag + " " + traceme_flag
         ),
-        exec_tools = [tfcompile_tool],
+        tools = [tfcompile_tool],
         visibility = visibility,
         testonly = testonly,
         # Run tfcompile on the build host since it's typically faster on the
@@ -281,7 +281,7 @@
             " --out_session_module=$(@D)/" + session_module_pb +
             " " + flags
         ),
-        exec_tools = [tfcompile_tool],
+        tools = [tfcompile_tool],
         visibility = visibility,
         testonly = testonly,
         local = 1,
diff --git a/tensorflow/compiler/mlir/tfr/build_defs.bzl b/tensorflow/compiler/mlir/tfr/build_defs.bzl
index c00b5c8..3c1dc5c 100644
--- a/tensorflow/compiler/mlir/tfr/build_defs.bzl
+++ b/tensorflow/compiler/mlir/tfr/build_defs.bzl
@@ -40,7 +40,7 @@
         srcs = [],
         outs = [name + ".inc.cc"],
         cmd = "$(location %s) --output=$@ --gen_register_op=true" % gen_op_lib_exec,
-        exec_tools = [":" + gen_op_lib_exec],
+        tools = [":" + gen_op_lib_exec],
         tags = tags,
     )
 
@@ -100,7 +100,7 @@
         srcs = [],
         outs = [name + ".mlir"],
         cmd = "$(location %s) --output=$@ --gen_register_op=false" % gen_tfr_lib_exec,
-        exec_tools = [":" + gen_tfr_lib_exec],
+        tools = [":" + gen_tfr_lib_exec],
         tags = tags,
     )
 
diff --git a/tensorflow/lite/build_def.bzl b/tensorflow/lite/build_def.bzl
index bca7a5a..25d6ab3 100644
--- a/tensorflow/lite/build_def.bzl
+++ b/tensorflow/lite/build_def.bzl
@@ -674,8 +674,7 @@
         cmd = (("$(locations :generate_examples) --toco $(locations {0}) " +
                 " --zip_to_output {1} {2} $(@D)").format(toco, file, flags)),
         outs = [file],
-        # `exec_tools` is required for PY3 compatibility in place of `tools`.
-        exec_tools = [
+        tools = [
             ":generate_examples",
             toco,
         ],
diff --git a/tensorflow/lite/delegates/flex/build_def.bzl b/tensorflow/lite/delegates/flex/build_def.bzl
index 5385446..8a138ac 100644
--- a/tensorflow/lite/delegates/flex/build_def.bzl
+++ b/tensorflow/lite/delegates/flex/build_def.bzl
@@ -73,7 +73,7 @@
         name = "%s_kernel_registration" % name,
         srcs = [list_ops_output],
         outs = [header],
-        exec_tools = [tool],
+        tools = [tool],
         message = "Processing %s..." % list_ops_output,
         cmd = ("$(location " + tool + ")" +
                " --default_ops=\"\"" +
diff --git a/tensorflow/lite/experimental/acceleration/compatibility/BUILD b/tensorflow/lite/experimental/acceleration/compatibility/BUILD
index 6c5a32b..e748c5a 100644
--- a/tensorflow/lite/experimental/acceleration/compatibility/BUILD
+++ b/tensorflow/lite/experimental/acceleration/compatibility/BUILD
@@ -99,7 +99,7 @@
         --output_source_file $(location :devicedb-sample.cc) \
         --array_variable_name g_tflite_acceleration_devicedb_sample_binary
     """,
-    exec_tools = [":convert_binary_to_cc_source"],
+    tools = [":convert_binary_to_cc_source"],
 )
 
 cc_library(
@@ -142,7 +142,7 @@
         --output_source_file $(location :gpu_compatibility_binary.cc) \
         --array_variable_name g_tflite_acceleration_gpu_compatibility_binary
     """,
-    exec_tools = [":convert_binary_to_cc_source"],
+    tools = [":convert_binary_to_cc_source"],
 )
 
 cc_library(
diff --git a/tensorflow/python/tools/BUILD b/tensorflow/python/tools/BUILD
index 0a3ad2b..2941ac7 100644
--- a/tensorflow/python/tools/BUILD
+++ b/tensorflow/python/tools/BUILD
@@ -399,7 +399,7 @@
     cmd = (
         "$(location :make_aot_compile_models) --out_dir $(@D)"
     ),
-    exec_tools = [":make_aot_compile_models"],
+    tools = [":make_aot_compile_models"],
     tags = ["no_rocm"],
 )
 
diff --git a/tensorflow/python/tools/api/generator/api_gen.bzl b/tensorflow/python/tools/api/generator/api_gen.bzl
index fb9fd65..45355c9 100644
--- a/tensorflow/python/tools/api/generator/api_gen.bzl
+++ b/tensorflow/python/tools/api/generator/api_gen.bzl
@@ -139,7 +139,7 @@
             " --use_relative_imports=True $(OUTS)"
         ),
         srcs = srcs,
-        exec_tools = [":" + api_gen_binary_target],
+        tools = [":" + api_gen_binary_target],
         visibility = [
             "//tensorflow:__pkg__",
             "//tensorflow/tools/api/tests:__pkg__",
diff --git a/tensorflow/tools/compatibility/BUILD b/tensorflow/tools/compatibility/BUILD
index a15014f..1aa76fb 100644
--- a/tensorflow/tools/compatibility/BUILD
+++ b/tensorflow/tools/compatibility/BUILD
@@ -219,7 +219,7 @@
            " --infile $(location testdata/test_file_v0_11.py)" +
            " --outfile $(location test_file_v1_0.py)" +
            " --reportfile $(location report.txt)"),
-    exec_tools = [":tf_upgrade"],
+    tools = [":tf_upgrade"],
 )
 
 py_test(
@@ -246,7 +246,7 @@
            " --outfile $(location test_file_v2_0.py)" +
            " --reportfile $(location report_v2.txt) && " +
            "sed -i'.original' 's/_TEST_VERSION = 1/_TEST_VERSION = 2/g' $(location test_file_v2_0.py)"),
-    exec_tools = [":tf_upgrade_v2"],
+    tools = [":tf_upgrade_v2"],
 )
 
 py_test(