[Howto]: Use mysqldump-secure in non default PHP containers when running more than one PHP version.

### Have you already checked elsewhere?

- [X] I have read the [Devilbox documentation](https://devilbox.readthedocs.io/en/latest/)
- [X] I have checked the [Devilbox Troubleshooting Guide](https://devilbox.readthedocs.io/en/latest/)
- [X] I have checked the [Devilbox FAQ](https://devilbox.readthedocs.io/en/latest/support/faq.html)
- [X] I have checked the [Devilbox Howto](https://devilbox.readthedocs.io/en/latest/support/howto.html)
- [X] I have checked the [Devilbox Forum](https://devilbox.discourse.group/)
- [X] I have checked [existing issues](https://github.com/cytopia/devilbox/issues)
- [X] I have googled already with no luck
- [ ] I have not done any of the above

### What are you struggling with?

When using multiple PHP versions, mysqldump-secure does not work in the non default containers without editing /etc/mysqldump-secure.cnf

After manually editing mysqldump-secure.cnf, mysqldump-secure works but only backs up inside the container and does not back up to the host folder.

mysqldump-secure only works inside the default PHP container.

### What have you tried already?

Editing mysqlsecure.cnf but still does not backup to host non container backup directory.

### What is your goal?

To be able to use mysqldump-secure inside any php container and not just the default php container.