Add MariaDB support for Uptime-Kuma v2

[sheyabernstein]

Description of the change

This PR adds support for using MariaDB as a database backend for Uptime-Kuma using Bitnami's chart. Currently in beta, this feature allows users to choose between the default SQLite or MariaDB for storing Uptime-Kuma data. MariaDB support includes environment variable configuration, secret handling for database credentials, and persistence options for MariaDB data.

Benefits

Provides the option to use MariaDB instead of SQLite for a more scalable database backend.

Possible drawbacks

Applicable issues

• fixes #

Additional information

• MariaDB support in Uptime-Kuma is still in beta. This chart was tested with 2.0.0-beta.1.
• This update is designed to be backward-compatible with existing database configurations.

Checklist

• Chart version bumped in Chart.yaml according to semver.
• Variables are documented in the README.md

[amrap030]

Hello, what is the status for this PR? I would be glad if this could be released :)

[dirsigler]

Hey @sheyabernstein ,

thank you very much for this feature!
I'll try to review it today or latest this week and approve/comment appropiately.

Thank you very much for your patience...

CC: @amrap030

[amrap030]

@dirsigler Thank you, that would be great :)

[sheyabernstein]

@dirsigler have you had the chance to review this PR yet?