Bump phpunit/phpunit from 7.5.20 to 9.3.11

Bumps [phpunit/phpunit](https://github.com/sebastianbergmann/phpunit) from 7.5.20 to 9.3.11.
- [Release notes](https://github.com/sebastianbergmann/phpunit/releases)
- [Changelog](https://github.com/sebastianbergmann/phpunit/blob/master/ChangeLog-9.3.md)
- [Commits](https://github.com/sebastianbergmann/phpunit/compare/7.5.20...9.3.11)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

composer.json

@@ -55,7 +55,7 @@
     "require-dev": {
         "swoole/ide-helper": "4.5.2",
         "appwrite/sdk-generator": "master",
-        "phpunit/phpunit": "^7.0"
+        "phpunit/phpunit": "^9.3"
     },
     "repositories": [
         {