Bump maglnet/composer-require-checker from 1.1.0 to 2.1.0

Bumps [maglnet/composer-require-checker](https://github.com/maglnet/ComposerRequireChecker) from 1.1.0 to 2.1.0.
- [Release notes](https://github.com/maglnet/ComposerRequireChecker/releases)
- [Changelog](https://github.com/maglnet/ComposerRequireChecker/blob/master/CHANGELOG.md)
- [Commits](maglnet/ComposerRequireChecker@1.1.0...2.1.0)

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

composer.json

@@ -21,7 +21,7 @@
     "require-dev": {
         "harmonyio/php-codesniffer-ruleset": "^1.0.0-rc1",
         "harmonyio/phpunit-extension": "^1.0.0-rc1",
-        "maglnet/composer-require-checker": "^1.1.0",
+        "maglnet/composer-require-checker": "^1.1.0 || ^2.0.0",
         "phpunit/phpunit": "^7.5.1",
         "slevomat/coding-standard": "^4.8.6",
         "squizlabs/php_codesniffer": "^3.4.0"