Don't run benchmarks from fork

Author: christiangnrd

.buildkite/pipeline.yml

@@ -154,7 +154,8 @@ steps:
           os: "macos"
           arch: "aarch64"
         if: |
-          build.message =~ /\[only benchmarks\]/ ||
+          build.pull_request.repository.fork &&
+          (build.message =~ /\[only benchmarks\]/ ||
           build.message !~ /\[only/ && !build.pull_request.draft &&
-            build.message !~ /\[skip benchmarks\]/
+            build.message !~ /\[skip benchmarks\]/)
         timeout_in_minutes: 30