[7.2.0] Stop listing `.gcno` files as outputs when using LLVM coverage map format

[bazel-io]

Forked from #22132

[bazel-io]

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

src/main/java/com/google/devtools/build/lib/rules/cpp/CompileBuildVariables.java

cc: @bazelbuild/triage

[iancha1992]

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

src/main/java/com/google/devtools/build/lib/rules/cpp/CompileBuildVariables.java

cc: @bazelbuild/triage

cc: @brentleyjones @fmeum @lberki @c-mita

[c-mita]

Created https://github.com/bazelbuild/bazel/pull/22275 manually