This class was only used in two places, both on the results screen, but
was holding references to `OsuPlayfield` game-wide (due to unrelated
issues, but still).
Because I can't really think of future use cases for this, and running
the calculation twice at results screen isn't a huge overhead, let's
just do that for now to keep things simple.
A custom divisor like 24 or 32 will result in a range containing
many divisors that are already in the `Common` and `Triplets` presets.
When this happens, it can become impossible to cycle between presets,
because the preset can only be changed if the new divisor isn't already
contained within the current preset's range.