[7.4.0] Automatically ignore vendor dir for finding packages

[bazel-io]

Forked from #23771

[bazel-io]

Cherry-pick was attempted but there were merge conflicts in the following file(s). Please resolve manually.

src/test/java/com/google/devtools/build/lib/buildtool/BUILD
src/test/java/com/google/devtools/build/lib/buildtool/ProjectResolutionTest.java
src/test/java/com/google/devtools/build/lib/pkgcache/IncrementalLoadingTest.java
src/test/java/com/google/devtools/build/lib/skyframe/GlobTestBase.java

cc: @bazelbuild/triage

[iancha1992]

Cherry-pick was attempted but there were merge conflicts in the following file(s). Please resolve manually.

src/test/java/com/google/devtools/build/lib/buildtool/BUILD src/test/java/com/google/devtools/build/lib/buildtool/ProjectResolutionTest.java src/test/java/com/google/devtools/build/lib/pkgcache/IncrementalLoadingTest.java src/test/java/com/google/devtools/build/lib/skyframe/GlobTestBase.java

cc: @bazelbuild/triage

cc: @meteorcloudy @Wyverald @gregestren

[meteorcloudy]

Manually backporting at #23919