[UAS-SCOUT] Update PHPUnit action to version 4 and set version to 9.5

Updated the PHPUnit GitHub Action to version 4 and specified the PHPUnit version to 9.5 in the CI configuration. This ensures compatibility with the latest features and improvements in PHPUnit.

Author: daanrijpkemacb

.github/workflows/ci.yml

@@ -35,8 +35,9 @@ jobs:
               run: vendor/bin/phpcs --standard=PSR12 src tests
 
             - name: PHPUnit Tests
-              uses: php-actions/phpunit@v3
+              uses: php-actions/phpunit@v4
               with:
                   php_version: ${{ matrix.php-version }}
+                  version: 9.5
                   bootstrap: ./vendor/autoload.php
                   configuration: ./.github/workflows/phpunit.xml