check concurrency on PR level with one running and one pending performance tests (#1401)

Workflow has concurrency reintroduced with different set of rules. New expected behavior is to check concurrency on PR level with one running and one pending performance tests. In case of multiple commits in same PR, always the latest commit is queued after initiated performance test execution is completed. Any other PRs/commits are in pending/queued state

.github/workflows/performance.yaml

@@ -26,6 +26,8 @@ on:
         required: true
         default: '-s'
 
+concurrency: "perftest-${{ github.head_ref ||  github.base_ref || 'schedule' }}"
+
 jobs:
   release:
     uses: rocmsoftwareplatform/migraphx-benchmark/.github/workflows/perf-test.yml@main