Update permissions

Author: adam-fowler

.github/workflows/benchmark.yml

@@ -22,6 +22,7 @@ jobs:
     permissions:
       issues: write
       pull-requests: write
+      contents: read
 
     strategy:
       matrix:
@@ -92,4 +93,4 @@ jobs:
           comment-tag: benchmark
       - name: Exit with correct status
         run: |
-          exit ${{ env.exitStatus }}
+          exit ${{ env.exitStatus }}