Update composer.local.json Example To Not Break MediaWiki Installation

[BPowell76]

Update new composer.local.json code block to include extra section (as found in the sample file provided by MediaWiki) to not break MediaWiki installation when running composer update. Update syntax highlighting to include relevant languages. Having only a require section in the composer.local.json file will result in the MediaWiki installation breaking after running composer update. The wiki will continue to function fine until you try to save an edit/new page and then it generates an internal error because other packages were updated.

This PR is made in reference to: N/A

This PR addresses or contains:

• Fixes to installation docs to prevent composer update --no-dev breaking lastest stable MediaWiki installation.

This PR includes:

• N/A

Fixes # N/A

[malberts]

What exactly breaks? And what is not getting updated? It sounds like something else in your wiki might have an issue.

The original require block is correct and enough to update Mermaid's dependencies. If you need to include a wildcard in extra, then it's likely something else causing your problem.

[BPowell76]

What exactly breaks? And what is not getting updated? It sounds like something else in your wiki might have an issue.

The original require block is correct and enough to update Mermaid's dependencies. If you need to include a wildcard in extra, then it's likely something else causing your problem.

It breaks other extensions. As the installation docs are written it updates more than just mermaid when you run composer update --no-dev.

As I also mentioned, this is the official documentation from MediaWiki. See Composer - Using composer-merge-plugin - MediaWiki.

I already fixed the issue by doing this, but if you want an exact stack trace I can remove it and run the update again.

The CI tests need to be updated too. Just noticed that it's testing against the no longer supported version 1.39.