Filter out broken grpc example on Linux

We do the same in the `rules_swift` repo: https://github.com/bazelbuild/rules_swift/blob/b6a111ea475da15793dfa5dda7e3e3646658f407/.bazelci/presubmit.yml#L24-L27

modules/rules_swift/1.2.0/presubmit.yml

@@ -20,6 +20,7 @@ tasks:
     - "--action_env=PATH"
     build_targets:
     - "@rules_swift//examples/xplatform/..."
+    - "-@rules_swift//examples/xplatform/grpc/..." # TODO: Fix grpc on Linux
   verify_targets_macos:
     name: Verify build targets
     platform: macos