Bump symfony/mailgun-mailer from 7.3.1 to 8.0.0

Bumps [symfony/mailgun-mailer](https://github.com/symfony/mailgun-mailer) from 7.3.1 to 8.0.0.
- [Release notes](https://github.com/symfony/mailgun-mailer/releases)
- [Changelog](https://github.com/symfony/mailgun-mailer/blob/7.3/CHANGELOG.md)
- [Commits](symfony/mailgun-mailer@v7.3.1...v8.0.0)

---
updated-dependencies:
- dependency-name: symfony/mailgun-mailer
  dependency-version: 8.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

composer.json

@@ -36,7 +36,7 @@
         "spatie/laravel-schedule-monitor": "^4.0",
         "spatie/laravel-sitemap": "^7.2",
         "symfony/http-client": "^7.0",
-        "symfony/mailgun-mailer": "^7.0"
+        "symfony/mailgun-mailer": "^8.0"
     },
     "require-dev": {
         "barryvdh/laravel-debugbar": "^3.16",