only run test matrix when "app" or "test" changes

.gitlab-ci.yml

@@ -129,9 +129,13 @@ test:
   image: python:3.11-slim-bookworm
   stage: test
   rules:
-    - if: $CI_COMMIT_BRANCH
+    - if: $CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH
     - if: $CI_COMMIT_TAG
     - if: $CI_PIPELINE_SOURCE == "merge_request_event"
+    - if: $CI_COMMIT_BRANCH && $CI_COMMIT_BRANCH != $CI_DEFAULT_BRANCH
+      changes:
+        - app/**/*
+        - test/**/*
   variables:
     DATABASE: sqlite:///../app/db.sqlite
   parallel: