Add pull_request trigger for CI workflow on master branch

Previously, the CI workflow did not run on pull requests to the master branch.
This change ensures it triggers on such pull requests for better coverage.

- Added `pull_request` trigger to `.github/workflows/ci.yml` for `master` branch.

Author: HichemTab-tech

.github/workflows/ci.yml

@@ -5,6 +5,9 @@ on:
   release:
     types:
     - released
+  pull_request:
+    branches:
+      - master
 
 jobs:
   build: