try out concurrency group feature on quick regression as suggested by @junghans

.github/workflows/quick-regression.yml

@@ -8,6 +8,10 @@ on:
 
   workflow_dispatch:
 
+concurrency:
+  group: ${{ github.event_name }}-${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{github.event_name == 'pull_request'}}
+
 jobs:
   build:
     name: Build LAMMPS