consistent label on .cirun.yml & workflow yml

Author: ev-br

.github/workflows/run_cirun_graviton.yml

@@ -16,7 +16,7 @@ env:
  # GITHUB_TOKEN: ${{ secrets.OB_BENCH_TOKEN }}
  # BENCHMARKS_REPO: ev-br/ob-bench-asv
   ASV_CONFIG: asv.conf.json
-  MACHINE_NAME: github-actions-cirun-graviton  # to identify github actions machine as hostname changes everytime
+  MACHINE_NAME: cirun-aws-runner-graviton  # to identify github actions machine as hostname changes everytime
 
 jobs:
   build: