Ensure MailMessageLogger is active in tests

[BacLuc]

See: https://github.com/symfony/symfony/pull/60515#issuecomment-3448631876

Hopefully we can do this better.

Now it broke in one random case: https://github.com/ecamp/ecamp3/pull/8228/files#diff-bec0448f23ef04c115375d2515e2c230d351a01156bfa534b24990369b6356e9 but it would be good if we had a consistent way with which we are sure a feature is active or not.

[BacLuc]

Will fix itself once

• https://github.com/symfony/symfony/pull/61924 is released