Only upload benchmark results if not on a fork (#91)

* Only upload benchmark results if not on a fork

* Give benchmark workflow perms to comment on PRs too

* Update Benchmark.yml

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Co-authored-by: Hong Ge <3279477+yebai@users.noreply.github.com>

.github/workflows/Benchmark.yml

@@ -12,6 +12,7 @@ concurrency:
 
 permissions:
   contents: write
+  pull-requests: write
 
 jobs:
   benchmark:
@@ -52,4 +53,4 @@ jobs:
           alert-threshold: "200%"
           fail-on-alert: true
           benchmark-data-dir-path: benchmarks
-          auto-push: true
+          auto-push: ${{ !github.event.pull_request.head.repo.fork }} # Disable push for PRs from forks