require non-zero Psalm version in CI

Author: thunderer

Diff for: .github/workflows/test.yaml

@@ -36,7 +36,7 @@ jobs:
         continue-on-error: '${{ matrix.failure }}'
       - name: 'Psalm'
         run: |
-          composer require --dev vimeo/psalm
+          composer require --dev -W 'vimeo/psalm=^4.0|^5.0'
           php vendor/bin/psalm --shepherd --php-version=${{ matrix.php }}
         continue-on-error: '${{ matrix.failure }}'
       - name: 'Infection'