Revert flux_led to 0.89

[amelchio]

Description:

This reverts three previous flux_led PRs:

• Fix MagicHome LEDs with flux_led component #20733 – which addressed a real bug but unfortunately broke other setups.
• Fix flux_led only-white controllers (and remove explicit declaration as RGBW in automatic add) #22210 – which cleaned up some of the Fix MagicHome LEDs with flux_led component #20733 breakage but not all of it. @autinerd has since been MIA.
• Introduce support for color temperature #25503 – which was merged prematurely but only to beta. I believe @yeralin is working on completing it.

The reverts bring flux_led back to the 0.89 level, as suggested in #22161 (comment). This includes the bug that #20733 tried to fix but I think it has become clear that it must be fixed in a different way.

I kept in a single fix that seems unrelated, #22161 (comment).

The commits cross both Black and The Great Migration so this does not exactly match the original PRs.

Related issue (if applicable): fixes #23322

Checklist:

• The code change is tested and works locally.
• Local tests pass with tox.
• There is no commented out code in this PR.
• I have followed the [development checklist][dev-checklist]