Revert use of custom Bazel for macos_build in CI workflow

[cgrindel]

Remove the use of the custom Bazel in themacos_build.

    # Remove this when Keith's PR is merged and made available in a Bazel release.
    env:
      USE_BAZEL_VERSION: cgrindel/6.0.0-keith_patch

Background

Error from GitHub Actions run.

ERROR: /private/var/tmp/_bazel_runner/6ba398470370e09a654e1f7bdb97a6ab/external/io_bazel_stardoc/stardoc/BUILD:70:12: Target '@io_bazel_stardoc//stardoc:renderer' depends on toolchain '@local_config_cc//:cc-compiler-darwin', which cannot be found: error loading package '@local_config_cc//': cannot load '@local_config_cc_toolchains//:osx_archs.bzl': no such file'

Keith's PR with fix.

• Reference osx_archs.bzl from bazel_tools bazelbuild/bazel#13529

Chuck's custom Bazel release with Keith's patch

Related Issues:

• High rate of spurious CI failures on macOS machines bazelbuild/bazel#14459
• bazel build @local_config_cc//... failed on macOS Big Sur bazelbuild/bazel#14603