Remove toolchain/benchmarks from the manifest

Bug: http://b/325154580

It's not used in the platform and it's contents are being deleted in ag/26172084.

Change-Id: I42cb871df03188bddaf29ce0796a0e1d3fe12449
Merged-In: I97bb6da690031d73b240b00f7f921ae6698eaea4
diff --git a/default.xml b/default.xml
index 2246bef..5e8c01c 100644
--- a/default.xml
+++ b/default.xml
@@ -1328,7 +1328,6 @@
   <project path="test/vts-testcase/security" name="platform/test/vts-testcase/security" groups="vts,projectarch,pdk" />
   <project path="test/vts-testcase/vndk" name="platform/test/vts-testcase/vndk" groups="vts,pdk" />
   <project path="test/catbox" name="platform/test/catbox" />
-  <project path="toolchain/benchmark" name="toolchain/benchmark" />
   <project path="toolchain/pgo-profiles" name="toolchain/pgo-profiles" groups="pdk" clone-depth="1" />
   <project path="tools/aadevtools" name="platform/tools/aadevtools" groups="pdk" />
   <project path="tools/acloud" name="platform/tools/acloud" groups="tools,vts,projectarch,pdk,tradefed" />