GPUArrays `rand` seeding fails when container is bigger than workgroup size

[christiangnrd]

See linked comment below for context, but in short I'm getting different results than CI on the rand doctest that uses GPUArrays.default_rng(MtlArray)

I was just getting different results locally and figured if it's unstable between devices maybe better to filter it out but maybe we should look into that instead (in a future pr). Lmk if I should revert the regex filter.

Originally posted by @christiangnrd in JuliaGPU/Metal.jl#641 (comment)

[christiangnrd]

This is masked by the issue behind #614.