Fix deprecation v2 of actions/upload-artifact

Author: sfmok

.github/workflows/ci.yml

@@ -59,7 +59,7 @@ jobs:
         run: "vendor/bin/phpunit --coverage-clover=coverage.xml"
 
       - name: "Upload coverage file"
-        uses: "actions/upload-artifact@v2"
+        uses: "actions/upload-artifact@v4"
         with:
           name: "phpunit-${{ matrix.php-version }}-${{ matrix.dependencies }}-${{ hashFiles('composer.lock') }}.coverage"
           path: "coverage.xml"