fix: rm temporary Dockerfile at the end of script (#6449)

Author: LesnyRumcajs

.github/workflows/rpc-parity-report.yml

@@ -30,6 +30,7 @@ jobs:
             IMAGE="ghcr.io/chainsafe/forest:edge-fat"
           fi
           echo "FROM $IMAGE" > Dockerfile-RPC
+          trap 'rm -f Dockerfile-RPC' EXIT
           export FOREST_DOCKERFILE_OVERRIDE=Dockerfile-RPC
           ./scripts/tests/api_compare/setup.sh
         timeout-minutes: 30