fix(CI): adjust concurrency to cancel pending CIs on merge (#24258)

.github/workflows/core-build-nopch.yml

@@ -10,7 +10,14 @@ on:
       - synchronize
 
 concurrency:
-  group: ${{ github.head_ref }} || concat(${{ github.ref_name }}, ${{ github.workflow }})
+  # One concurrency group per workflow + ref.
+  #
+  # - PRs use `refs/pull/<PR_NUMBER>/merge`, so new commits cancel older
+  #   in-progress runs for the same PR.
+  # - When a PR is merged, a push to the target branch starts a new group,
+  #   canceling any still-running PR CI.
+  # - Branch pushes are isolated by ref.
+  group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
 permissions:

.github/workflows/core-build-pch.yml

@@ -10,7 +10,14 @@ on:
       - synchronize
 
 concurrency:
-  group: ${{ github.head_ref }} || concat(${{ github.ref_name }}, ${{ github.workflow }})
+  # One concurrency group per workflow + ref.
+  #
+  # - PRs use `refs/pull/<PR_NUMBER>/merge`, so new commits cancel older
+  #   in-progress runs for the same PR.
+  # - When a PR is merged, a push to the target branch starts a new group,
+  #   canceling any still-running PR CI.
+  # - Branch pushes are isolated by ref.
+  group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
 permissions:

.github/workflows/core_modules_build.yml

@@ -24,7 +24,14 @@ permissions:
   contents: read
 
 concurrency:
-  group: ${{ github.head_ref }} || concat(${{ github.ref_name }}, ${{ github.workflow }})
+  # One concurrency group per workflow + ref.
+  #
+  # - PRs use `refs/pull/<PR_NUMBER>/merge`, so new commits cancel older
+  #   in-progress runs for the same PR.
+  # - When a PR is merged, a push to the target branch starts a new group,
+  #   canceling any still-running PR CI.
+  # - Branch pushes are isolated by ref.
+  group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
 jobs:

.github/workflows/dashboard-ci.yml

@@ -16,7 +16,14 @@ on:
   workflow_dispatch:
 
 concurrency:
-  group: ${{ github.head_ref }} || concat(${{ github.ref_name }}, ${{ github.workflow }})
+  # One concurrency group per workflow + ref.
+  #
+  # - PRs use `refs/pull/<PR_NUMBER>/merge`, so new commits cancel older
+  #   in-progress runs for the same PR.
+  # - When a PR is merged, a push to the target branch starts a new group,
+  #   canceling any still-running PR CI.
+  # - Branch pushes are isolated by ref.
+  group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
 permissions:

.github/workflows/docker_build.yml

@@ -9,7 +9,14 @@ on:
       - synchronize
 
 concurrency:
-  group: ${{ github.head_ref }} || concat(${{ github.ref_name }}, ${{ github.workflow }})
+  # One concurrency group per workflow + ref.
+  #
+  # - PRs use `refs/pull/<PR_NUMBER>/merge`, so new commits cancel older
+  #   in-progress runs for the same PR.
+  # - When a PR is merged, a push to the target branch starts a new group,
+  #   canceling any still-running PR CI.
+  # - Branch pushes are isolated by ref.
+  group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
 env:

.github/workflows/tools_build.yml

@@ -9,7 +9,14 @@ on:
       - synchronize
 
 concurrency:
-  group: ${{ github.head_ref }} || concat(${{ github.ref_name }}, ${{ github.workflow }})
+  # One concurrency group per workflow + ref.
+  #
+  # - PRs use `refs/pull/<PR_NUMBER>/merge`, so new commits cancel older
+  #   in-progress runs for the same PR.
+  # - When a PR is merged, a push to the target branch starts a new group,
+  #   canceling any still-running PR CI.
+  # - Branch pushes are isolated by ref.
+  group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
 jobs:

.github/workflows/windows_build.yml

@@ -9,7 +9,14 @@ on:
       - synchronize
 
 concurrency:
-  group: ${{ github.head_ref }} || concat(${{ github.ref_name }}, ${{ github.workflow }})
+  # One concurrency group per workflow + ref.
+  #
+  # - PRs use `refs/pull/<PR_NUMBER>/merge`, so new commits cancel older
+  #   in-progress runs for the same PR.
+  # - When a PR is merged, a push to the target branch starts a new group,
+  #   canceling any still-running PR CI.
+  # - Branch pushes are isolated by ref.
+  group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
 jobs: