build(deps): bump symfony/mailer from 7.3.2 to 7.3.4

Bumps [symfony/mailer](https://github.com/symfony/mailer) from 7.3.2 to 7.3.4.
- [Release notes](https://github.com/symfony/mailer/releases)
- [Changelog](https://github.com/symfony/mailer/blob/7.3/CHANGELOG.md)
- [Commits](symfony/mailer@v7.3.2...v7.3.4)

---
updated-dependencies:
- dependency-name: symfony/mailer
  dependency-version: 7.3.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]