Only run the workflows on the master branch

Author: julienw

.github/workflows/test.yml

@@ -1,5 +1,15 @@
 name: test
-on: [push, pull_request]
+
+on:
+  # Trigger the workflow on push or pull request,
+  # but only for the master branch
+  push:
+    branches:
+      - master
+    pull_request:
+      branches:
+        - master
+
 jobs:
   test:
     runs-on: ubuntu-latest