Test against MariaDB 11.4 (the new LTS) in general matrix

[GuySartorelli]

MariaDB have decided to promote 11.4 to an LTS version outside of their newly adopted LTS release scheduling.

We recently made the decision to support LTS versions of MariaDB so we should update the matrix to test against this version, and make any code changes that are necessary for CI to be green.

It's unclear what this means for MariaDB 10.11 which was the LTS release until now, and was going to be the LTS for a while yet.

See the maintenance policy for timeline info

To decide

• We need to decide if we want to test against both of those (10.11 and 11.4), or just the latest LTS.
  • Decision: Only test the latest.

Acceptance criteria

• CMS 5 branches test MariaDB 11.4 is tested in CI
• CMS 4 branches test MariaDB 10.11. - turns out CMS 4 never ran mariadb in CI, so we won't change that.
• CI is green for all supported modules.
• Doc are updated to mentioned that we test only the latest LTS version of MariaDB.

PRs

• MNT Ignore narrow no-break space in regex in tests silverstripe-framework#11291
• ENH Test against latest MariaDB LTS release gha-ci#129
• DOC Clarify we test with the latest LTS for MariaDB and MySQL developer-docs#535

AFTER MERGING reassign to Guy to validate things are green.

[maxime-rainville]

Doesn't look like 11.4 has been released yet.

Validation

• Make sure 11.4 has release a stable version first
• Validate how much has changed between 10.11 and 11.4.
• Validate how much work will be needed to support both of them simultaneously.

[GuySartorelli]

11.4 is now stable

[emteknetnz]

Have released 1.11.0

Reassigning to Guy to validate that things (in particular framework) are green after re-run

[GuySartorelli]

https://github.com/silverstripe/silverstripe-framework/actions/runs/9689780523
Confirmed framework is happy running 11.4.2-MariaDB-ubu2404