The test was checking the test scene's own `SelectedMods` bindable
rather than the multiplayer screen's, and the former was never actually
being mutated by anything. Therefore the case would pass even on
`master` with the fix reverted.
This was in flyte's design (he was following discord) but doesn't feel
too correct when it's not aligned with anything else. We can revisit
this if/when we have better glyphs to represent channel types.
`PlayerLoader` is required in the sequence to get the game into the
correct state for gameplay right now. Applying ths simplest fix here.
Closes https://github.com/ppy/osu/issues/17351.