Update pr_criterion.yaml: use bare-metal runners

Author: scottgerring

.github/workflows/pr_criterion.yaml

@@ -5,7 +5,7 @@ jobs:
     name: run benchmark
     permissions:
       pull-requests: write
-    runs-on: ubuntu-latest
+    runs-on: self-hosted
     if: ${{ contains(github.event.pull_request.labels.*.name, 'performance') }}
     steps:
       - uses: actions/checkout@v4
@@ -28,4 +28,4 @@ jobs:
         with:
           cwd: opentelemetry-sdk
           features: rt-tokio,testing,metrics,logs,spec_unstable_metrics_views
-          branchName: ${{ github.base_ref }}
+          branchName: ${{ github.base_ref }}