chore: Bump the minimum required Symfony version to 6.4

- Drop support for Symfony 6 except the LTS version.
- Drop support for Symfony 5.

composer.json

@@ -22,9 +22,9 @@
         "fidry/filesystem": "^1.1",
         "jetbrains/phpstorm-stubs": "^v2022.2",
         "nikic/php-parser": "^4.12",
-        "symfony/console": "^5.2 || ^6.0",
-        "symfony/filesystem": "^5.2 || ^6.0",
-        "symfony/finder": "^5.2 || ^6.0",
+        "symfony/console": "^6.4",
+        "symfony/filesystem": "^6.4",
+        "symfony/finder": "^6.4",
         "thecodingmachine/safe": "^2.0"
     },
     "require-dev": {
@@ -34,7 +34,7 @@
         "humbug/box": "^4.5.1",
         "phpspec/prophecy-phpunit": "^2.0",
         "phpunit/phpunit": "^9.0",
-        "symfony/yaml": "^6.1"
+        "symfony/yaml": "^6.4"
     },
     "minimum-stability": "dev",
     "prefer-stable": true,