Show the PHPStan version

Also pin to the second to last released version for the GHA as the last one crashes.

(cherry picked from commit bf67a46)

Author: Michael Vasseur

.github/workflows/phpstan.yml

@@ -16,7 +16,7 @@ jobs:
       - uses: actions/checkout@v4
       - name: Install DOMjudge
         run: .github/jobs/baseinstall.sh admin
-      - uses: php-actions/phpstan@v3
+      - uses: php-actions/phpstan@v3.0.2
         with:
           configuration: phpstan.dist.neon
           path: webapp/src webapp/tests