perf: Optimize Cache::remove for value types that need drop

[malik672]

Optimize Cache::remove for value types that need drop by moving the stored entry out of the bucket instead of cloning the value and then dropping the original pair.

For types that do not need drop, remove keeps the old cheap clone path so small Copy-like values such as u64 do not pay extra work moving the whole (K, V) pair.

Criterion comparison:

Case	Before	After	Result
u64 -> u64	28.060 µs	26.312 µs	no meaningful change
u64 -> String(64b)	152.74 µs	71.014 µs	~55% faster