Use ref instead head_ref to cancelling jobs

.github/workflows/bootstrap.yml

@@ -2,7 +2,7 @@ name: Bootstrap
 
 # See: https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions#concurrency.
 concurrency:
-  group: ${{ github.head_ref }}-${{ github.workflow }}
+  group: ${{ github.ref }}-${{ github.workflow }}
   cancel-in-progress: true
 
 on:

.github/workflows/linux.yml

@@ -2,7 +2,7 @@ name: Linux
 
 # See: https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions#concurrency.
 concurrency:
-  group: ${{ github.head_ref }}-${{ github.workflow }}
+  group: ${{ github.ref }}-${{ github.workflow }}
   cancel-in-progress: true
 
 on:

.github/workflows/macos.yml

@@ -2,7 +2,7 @@ name: MacOS
 
 # See: https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions#concurrency.
 concurrency:
-  group: ${{ github.head_ref }}-${{ github.workflow }}
+  group: ${{ github.ref }}-${{ github.workflow }}
   cancel-in-progress: true
 
 on:

.github/workflows/quick-jobs.yml

@@ -2,7 +2,7 @@ name: Quick jobs
 
 # See: https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions#concurrency.
 concurrency:
-  group: ${{ github.head_ref }}-${{ github.workflow }}
+  group: ${{ github.ref }}-${{ github.workflow }}
   cancel-in-progress: true
 
 on:

.github/workflows/users-guide.yml

@@ -4,7 +4,7 @@ name: Users guide
 
 # See: https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions#concurrency.
 concurrency:
-  group: ${{ github.head_ref }}-${{ github.workflow }}
+  group: ${{ github.ref }}-${{ github.workflow }}
   cancel-in-progress: true
 
 on:

.github/workflows/windows.yml

@@ -2,7 +2,7 @@ name: Windows
 
 # See: https://docs.github.com/en/actions/reference/workflow-syntax-for-github-actions#concurrency.
 concurrency:
-  group: ${{ github.head_ref }}-${{ github.workflow }}
+  group: ${{ github.ref }}-${{ github.workflow }}
   cancel-in-progress: true
 
 on: