ci/cpu: cancel-in-progress

Author: Borda

.github/workflows/cpu-tests.yml

@@ -10,7 +10,7 @@ on:
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}-${{ github.head_ref }}
-  cancel-in-progress: ${{ github.ref != 'refs/heads/main' }}
+  cancel-in-progress: ${{ github.event_name == 'pull_request_target' }}
 
 defaults:
   run: