Bump symfony/mailgun-mailer from 5.4.21 to 6.2.10

Bumps [symfony/mailgun-mailer](https://github.com/symfony/mailgun-mailer) from 5.4.21 to 6.2.10.
- [Release notes](https://github.com/symfony/mailgun-mailer/releases)
- [Changelog](https://github.com/symfony/mailgun-mailer/blob/6.2/CHANGELOG.md)
- [Commits](symfony/mailgun-mailer@v5.4.21...v6.2.10)

---
updated-dependencies:
- dependency-name: symfony/mailgun-mailer
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

composer.json

@@ -87,7 +87,7 @@
         "symfony/intl": "^5.4",
         "symfony/mailchimp-mailer": "^5.4",
         "symfony/mailer": "^5.4",
-        "symfony/mailgun-mailer": "^5.4",
+        "symfony/mailgun-mailer": "^6.2",
         "symfony/messenger": "^5.4",
         "symfony/mime": "^5.4",
         "symfony/monolog-bundle": "^3.7",