Stop redundant builds

.github/workflows/build.yml

@@ -4,6 +4,9 @@ on:
     branches:
       - main
   pull_request:
+concurrency:
+  group: ${{ github.ref }}
+  cancel-in-progress: true
 jobs:
   build-static-assets:
     runs-on: ubuntu-latest

.github/workflows/copyright_notice.yml

@@ -3,6 +3,9 @@ on:
   pull_request:
 permissions:
   contents: write
+concurrency:
+  group: ${{ github.ref }}
+  cancel-in-progress: true
 jobs:
   copyright_notice:
     runs-on: ubuntu-latest

.github/workflows/tests.yml

@@ -4,6 +4,9 @@ on:
     branches:
       - main
   pull_request:
+concurrency:
+  group: ${{ github.ref }}
+  cancel-in-progress: true
 jobs:
   unit_tests:
     runs-on: ubuntu-latest