Cancel old runs when a new commit is pushed (#37)

This helps not wasting workflow resources

Author: lucic71

.github/workflows/codeql.yml

@@ -6,6 +6,10 @@ on:
       - master
   pull_request:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   analyze:
     name: Analyze ${{ matrix.language }}

.github/workflows/format.yml

@@ -6,6 +6,10 @@ on:
       - master
   pull_request:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   format:
     runs-on: ubuntu-latest

.github/workflows/run-tests.yml

@@ -6,6 +6,10 @@ on:
       - master
   pull_request:
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   test:
     strategy: