fix(mariadb plugin): Fix warning by using 'mariadb-install-db' instead of 'mysql_install_db'. #2910

[jefft]

Summary

Change setup_db.sh (run via init hook) to user the proper MariaDB executable name 'mariadb-install-db', rather than its compatibility symlink 'mysql_install_db'. This prevents users seeing the note:

.../.devbox/nix/profile/default/bin/mysql_install_db: Deprecated program name. It will be removed in a future release, use 'mariadb-install-db' instead 

Fixes #2910

How was it tested?

mkdir /tmp/mariadbtest
cd /tmp/mariadbtest
devbox init
devbox add mariadb
devbox services up

No longer prints the deprecation warning:

jturner@jturner-desktop:/tmp/mariadbtest$ devbox services up
Info: Ensuring packages are installed.
✓ Computed the Devbox environment.
Installing MariaDB/MySQL system tables in '/tmp/mariadbtest/.devbox/virtenv/mariadb/data' ...
OK
...

Community Contribution License

All community contributions in this pull request are licensed to the project
maintainers under the terms of the
Apache 2 License.

By creating this pull request, I represent that I have the right to license the
contributions to the project maintainers under the Apache 2 License as stated in
the
Community Contribution License.