GHA CI: Don't cancel CI builds on non-pull-request branches

Fix up 2652c73a4f.
PR #16558.

.github/workflows/ci_file_health.yaml

@@ -3,7 +3,7 @@ name: CI - File health
 on: [pull_request, push]
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.head_ref }}
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
   cancel-in-progress: ${{ github.head_ref != '' }}
 
 jobs:

.github/workflows/ci_macos.yaml

@@ -3,7 +3,7 @@ name: CI - macOS
 on: [pull_request, push]
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.head_ref }}
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
   cancel-in-progress: ${{ github.head_ref != '' }}
 
 jobs:

.github/workflows/ci_ubuntu.yaml

@@ -3,7 +3,7 @@ name: CI - Ubuntu
 on: [pull_request, push]
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.head_ref }}
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
   cancel-in-progress: ${{ github.head_ref != '' }}
 
 jobs:

.github/workflows/ci_webui.yaml

@@ -3,7 +3,7 @@ name: CI - WebUI
 on: [pull_request, push]
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.head_ref }}
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
   cancel-in-progress: ${{ github.head_ref != '' }}
 
 jobs:

.github/workflows/ci_windows.yaml

@@ -3,7 +3,7 @@ name: CI - Windows
 on: [pull_request, push]
 
 concurrency:
-  group: ${{ github.workflow }}-${{ github.head_ref }}
+  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
   cancel-in-progress: ${{ github.head_ref != '' }}
 
 jobs: