refactor: Mark internal and `python` extension as reproducible (#1892)

This avoids unnecessary lockfile entries for users of rules_python.

---------

Co-authored-by: aignas <240938+aignas@users.noreply.github.com>
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1e993a7..3b0d526 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -23,6 +23,11 @@
 
 ### Changed
 
+* (deps): Bumped `bazel_skylib` to 1.6.1.
+* (bzlmod): The `python` and internal `rules_python` extensions have been
+  marked as `reproducible` and will not include any lock file entries from now
+  on.
+
 ### Fixed
 
 * (gazelle) Remove `visibility` from `NonEmptyAttr`.
@@ -54,7 +59,7 @@
   sorted in the attributes section. We are also removing values that are not
   default in order to reduce the size of the lock file.
 * (coverage) Bump `coverage.py` to [7.4.3](https://github.com/nedbat/coveragepy/blob/master/CHANGES.rst#version-743--2024-02-23).
-* (deps): Bumped bazel_features to 1.9.1 to detect optional support
+* (deps): Bumped `bazel_features` to 1.9.1 to detect optional support
   non-blocking downloads.
 * (deps): Updated `pip_tools` to >= 7.4.0
 * (toolchains): Change some old toolchain versions to use [20240224] release to
diff --git a/MODULE.bazel b/MODULE.bazel
index 3e62ab7..8acde16 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -5,7 +5,7 @@
 )
 
 bazel_dep(name = "bazel_features", version = "1.9.1")
-bazel_dep(name = "bazel_skylib", version = "1.3.0")
+bazel_dep(name = "bazel_skylib", version = "1.6.1")
 bazel_dep(name = "rules_cc", version = "0.0.9")
 bazel_dep(name = "platforms", version = "0.0.4")
 
@@ -14,7 +14,6 @@
 bazel_dep(name = "protobuf", version = "21.7", repo_name = "com_google_protobuf")
 
 internal_deps = use_extension("//python/private/bzlmod:internal_deps.bzl", "internal_deps")
-internal_deps.install()
 use_repo(
     internal_deps,
     "rules_python_internal",
diff --git a/gazelle/MODULE.bazel b/gazelle/MODULE.bazel
index 1d01f49..6ae7719 100644
--- a/gazelle/MODULE.bazel
+++ b/gazelle/MODULE.bazel
@@ -4,7 +4,7 @@
     compatibility_level = 1,
 )
 
-bazel_dep(name = "bazel_skylib", version = "1.5.0")
+bazel_dep(name = "bazel_skylib", version = "1.6.1")
 bazel_dep(name = "rules_python", version = "0.18.0")
 bazel_dep(name = "rules_go", version = "0.41.0", repo_name = "io_bazel_rules_go")
 bazel_dep(name = "gazelle", version = "0.33.0", repo_name = "bazel_gazelle")
diff --git a/python/extensions/BUILD.bazel b/python/extensions/BUILD.bazel
index a9dede4..eb095ab 100644
--- a/python/extensions/BUILD.bazel
+++ b/python/extensions/BUILD.bazel
@@ -37,6 +37,7 @@
     visibility = ["//:__subpackages__"],
     deps = [
         "//python/private:util_bzl",
+        "//python/private/bzlmod:bazel_features_bzl",
         "//python/private/bzlmod:python_bzl",
     ],
 )
diff --git a/python/private/bzlmod/BUILD.bazel b/python/private/bzlmod/BUILD.bazel
index 0ec95e4..9edd338 100644
--- a/python/private/bzlmod/BUILD.bazel
+++ b/python/private/bzlmod/BUILD.bazel
@@ -45,7 +45,7 @@
 
 bzl_library(
     name = "bazel_features_bzl",
-    srcs = ["@bazel_features//:bzl_files"],
+    deps = ["@bazel_features//:features"],
 )
 
 bzl_library(
diff --git a/python/private/bzlmod/internal_deps.bzl b/python/private/bzlmod/internal_deps.bzl
index aadf2cc..62ca71f 100644
--- a/python/private/bzlmod/internal_deps.bzl
+++ b/python/private/bzlmod/internal_deps.bzl
@@ -8,18 +8,15 @@
 
 "Python toolchain module extension for internal rule use"
 
+load("@bazel_skylib//lib:modules.bzl", "modules")
 load("//python/pip_install:repositories.bzl", "pip_install_dependencies")
 load("//python/private:internal_config_repo.bzl", "internal_config_repo")
 
-# buildifier: disable=unused-variable
-def _internal_deps_impl(module_ctx):
+def _internal_deps():
     internal_config_repo(name = "rules_python_internal")
     pip_install_dependencies()
 
-internal_deps = module_extension(
-    doc = "This extension to register internal rules_python dependecies.",
-    implementation = _internal_deps_impl,
-    tag_classes = {
-        "install": tag_class(attrs = dict()),
-    },
+internal_deps = modules.as_extension(
+    _internal_deps,
+    doc = "This extension registers internal rules_python dependencies.",
 )
diff --git a/python/private/bzlmod/python.bzl b/python/private/bzlmod/python.bzl
index 5862f00..f8be271 100644
--- a/python/private/bzlmod/python.bzl
+++ b/python/private/bzlmod/python.bzl
@@ -14,6 +14,7 @@
 
 "Python toolchain module extensions for use with bzlmod"
 
+load("@bazel_features//:features.bzl", "bazel_features")
 load("//python:repositories.bzl", "python_register_toolchains")
 load("//python/private:toolchains_repo.bzl", "multi_toolchain_aliases")
 load("//python/private:util.bzl", "IS_BAZEL_6_4_OR_HIGHER")
@@ -230,6 +231,11 @@
             debug_info = json.encode_indent(debug_info),
         )
 
+    if bazel_features.external_deps.extension_metadata_has_reproducible:
+        return module_ctx.extension_metadata(reproducible = True)
+    else:
+        return None
+
 def _fail_duplicate_module_toolchain_version(version, module):
     fail(("Duplicate module toolchain version: module '{module}' attempted " +
           "to use version '{version}' multiple times in itself").format(