Remove contracts from the Allocator interface.
Remove contracts from the Allocator interface.

These caused reading of uninitialized memory and didn't have an effect anyway.

rejectedsoftware/vibe.d,Geod24/vibe.d,etcimon/vibe.d,DBankov/vibe.d,gedaiu/vibe.d,chalucha/vibe.d,etcimon/vibe.d