Remove @(require_results) from `arena_init_X` in `virtual.odin`

[karl-zylinski]

Since you can init a growing arena like this (which is how I usually do it):

arena: vmem.Arena
arena_allocator := vmem.arena_allocator(&arena)

And then use for example a dynamic array to grow that arena without having to handle any allocation error, then you shouldn't be required to handle the initial error of the arena init either.

[gingerBill]

No. I added that on purpose.