fix: catch OverflowError in num() alongside ValueError

[koteshyelamati]

Problem

num() only catches ValueError when calling int(count), but int(float('inf')) raises OverflowError — which is not a subclass of ValueError — so the intended BadNumValueError is never raised:

import inflect
p = inflect.engine()
p.num(float('inf'))
# OverflowError: cannot convert float infinity to integer
# Expected: BadNumValueError

Fix

Add OverflowError to the except tuple so all numeric conversion failures produce the documented BadNumValueError.