action: concurrency fix

Author: pymumu

.github/workflows/merge-request-ascend.yml

@@ -6,7 +6,7 @@ on:
       - main
 
 concurrency: 
-  group: ${{ github.head_ref && github.workflow}}
+  group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
 env:

.github/workflows/merge-request-cuda.yml

@@ -6,7 +6,7 @@ on:
       - main
 
 concurrency: 
-  group: ${{ github.head_ref && github.workflow}}
+  group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
 env: