Update pull-request-artifacts config

.github/workflows/main_matrix.yml

@@ -212,6 +212,13 @@ jobs:
           repository: ${{github.event.pull_request.head.repo.full_name}}
 
   gather-artifacts:
+    permissions:
+    # Required to upload/save artifact, otherwise you'll get
+    # "Error: Resource not accessible by integration"
+    contents: write
+    # Required to post comment, otherwise you'll get
+    # "Error: Resource not accessible by integration"
+    pull-requests: write
     runs-on: ubuntu-latest
     needs:
       [
@@ -292,7 +299,6 @@ jobs:
           artifacts-token: ${{ secrets.ARTIFACTS_TOKEN }}
           artifacts-repo: meshtastic/artifacts
           artifacts-branch: device
-          artifacts-prefix: pr
           artifacts: ./firmware-${{ steps.version.outputs.version }}.zip
 
   release-artifacts: