Regressed in https://github.com/ppy/osu/pull/25171.
The old code was kinda dependent on correct order of setting `Disabled`.
`CatchHitObjectComposer` would disable distance spacing in its BDL, and
then via the base `DistancedHitObjectComposer.LoadComplete()`, the
slider would be faded out. The switch to composition broke that
ordering.
To fix, stop relying on ordering and just respond to changes as they
come. That's what bindables are for.
