ci: Fix usage of concurrency in branches other than master

.github/workflows/cygwin.yml

@@ -1,7 +1,7 @@
 name: cygwin
 
 concurrency:
-  group: cygwin-${{ github.head_ref }}
+  group: cygwin-${{ github.head_ref || github.ref }}
   cancel-in-progress: true
 
 on:

.github/workflows/file_format.yml

@@ -3,7 +3,7 @@ name: File format check
 on: [push, pull_request]
 
 concurrency:
-  group: file_fmt-${{ github.head_ref }}
+  group: file_fmt-${{ github.head_ref || github.ref }}
   cancel-in-progress: true
 
 permissions:

.github/workflows/images.yml

@@ -1,7 +1,7 @@
 name: CI image builder
 
 concurrency:
-  group: img_builder-${{ github.head_ref }}
+  group: img_builder-${{ github.head_ref || github.ref }}
   cancel-in-progress: true
 
 on:

.github/workflows/lint.yml

@@ -1,7 +1,7 @@
 name: Lint
 
 concurrency:
-  group: lint-${{ github.head_ref }}
+  group: lint-${{ github.head_ref || github.ref }}
   cancel-in-progress: true
 
 on:

.github/workflows/macos.yml

@@ -1,7 +1,7 @@
 name: macos
 
 concurrency:
-  group: macos-${{ github.head_ref }}
+  group: macos-${{ github.head_ref || github.ref }}
   cancel-in-progress: true
 
 on:

.github/workflows/msys2.yml

@@ -1,7 +1,7 @@
 name: msys2
 
 concurrency:
-  group: msys2-${{ github.head_ref }}
+  group: msys2-${{ github.head_ref || github.ref }}
   cancel-in-progress: true
 
 on:

.github/workflows/nonative.yml

@@ -1,7 +1,7 @@
 name: Cross-only compilation environment
 
 concurrency:
-  group: nonative-${{ github.head_ref }}
+  group: nonative-${{ github.head_ref || github.ref }}
   cancel-in-progress: true
 
 on:

.github/workflows/os_comp.yml

@@ -1,7 +1,7 @@
 name: linux
 
 concurrency:
-  group: linux-${{ github.head_ref }}
+  group: linux-${{ github.head_ref || github.ref }}
   cancel-in-progress: true
 
 on:

.github/workflows/unusedargs_missingreturn.yml

@@ -10,7 +10,7 @@ env:
   FFLAGS: "-fimplicit-none"
 
 concurrency:
-  group: unusedargs-${{ github.head_ref }}
+  group: unusedargs-${{ github.head_ref || github.ref }}
   cancel-in-progress: true
 
 on: