Enable tests for PRs that don't merge into main or develop

.github/workflows/test_suite.yml

@@ -1,10 +1,20 @@
 name: compile code and tests
 
 on:
+  # if you wish to skip running CI please don't change this section, instead
+  # prefix the following notation in the title of your commit message e.g.,
+  #
+  # [skip ci] my commit message
+  #
+  # For more information, please read the GitHub
+  # [documentation](https://docs.github.com/en/actions/managing-workflow-runs-and-deployments/managing-workflow-runs/skipping-workflow-runs)
+  #
+  # Note: You will not be able to merge into develop or main without running CI. To run CI either:
+  # - edit the last commit message using `git commit --amend` and remove the tag "[skip ci]" or,
+  # - create a new commit without a "[skip ci]" tag
   push:
     branches: [ main, develop ]
   pull_request:
-    branches: [ main, develop ]
     paths:
       - '.github/workflows/test_suite.yml'
       - '**.cdl'