feat: upgrade to PHPUnit 9

Author: lynnntropy

.github/workflows/main.yml

@@ -23,7 +23,7 @@ jobs:
         run: composer install
 
       - name: Run tests
-        run: php vendor/bin/phpunit --coverage-text --coverage-clover build/logs/clover.xml
+        run: php vendor/bin/phpunit
 
       - name: Publish code coverage
         if: ${{ github.ref == 'refs/heads/master' && matrix.php == '8.0' && matrix.os == 'ubuntu-latest' }}

composer.json

@@ -24,6 +24,6 @@
   },
   "require-dev": {
     "symfony/var-dumper": "^4.3",
-    "phpunit/phpunit": "^8.2"
+    "phpunit/phpunit": "^9"
   }
 }