chore: disable macos-cmake GHA CI (googleapis#15534)

Author: jinseopkim0

.github/workflows/test-runner.yml

@@ -113,6 +113,8 @@ jobs:
       execute-integration-tests: true
     secrets: inherit
   macos-cmake:
+    # Disabled
+    if: false
     name: macOS-CMake
     needs: [pre-flight]
     uses: ./.github/workflows/macos-cmake.yml
@@ -155,7 +157,7 @@ jobs:
     # Wait until all the other jobs have completed.
     needs:
       - macos-bazel
-      - macos-cmake
+      # macos-cmake is disabled
       - windows-bazel
       - windows-cmake
     # Run even if the other jobs failed or were skipped.