Enable Style/FloatDivision cop

Ref: #42182 (closed)

What does this MR do and why?

This MR enables the Style/FloatDivision cop. In a follow-up MR, we can run the auto-correction which should take care of the existing offences.

Screenshots or screen recordings

# bad
a.to_f / b.to_f

# good
a.to_f / b
a / b.to_f

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.