Give check-changeset job pull request write permissions (#8833)

Author: dlarocque

.github/workflows/check-changeset.yml

@@ -28,6 +28,9 @@ jobs:
     name: Check changeset vs changed files
     runs-on: ubuntu-latest
 
+    permissions:
+      pull-requests: write
+
     steps:
     - name: Checkout Repo
       uses: actions/checkout@v4
@@ -89,4 +92,4 @@ jobs:
     # Don't want it to throw before editing the comment.
     - name: Fail if checker script logged a blocking failure
       if: ${{steps.check-changeset.outputs.BLOCKING_FAILURE == 'true'}}
-      run: exit 1
+      run: exit 1