Disable randGen test because it is failing on macOS (the random number generator, the way we use it, is non-portable).

PiperOrigin-RevId: 877684728

Author: agutkin

.github/workflows/bazel_arm64_macos.yml

@@ -58,8 +58,12 @@ jobs:
           run: |
             ./$BAZEL build -c opt //...
         - name: Test
-          run: |
-            ./$BAZEL test -c opt --test_size_filters=-enormous --test_output=errors //...
+          run: >-
+            ./$BAZEL test -c opt
+            --test_size_filters=-enormous
+            --test_output=errors
+            --test_filter=PywrapFstTest.testRandGen*
+            //...
         - name: Save new cache for main
           if: github.ref == 'refs/heads/main'
           uses: actions/cache/save@v5