Artifact Cache: Consider CPU Feature Flags When Loading Artifacts

[theduke]

Module artifacts are compiled with specific CPU feature flags.

This means artifacts aren't universally compatible, but can only run on CPUs that support all the features the artifact was compiled with.

It is possible to end up with a module cache directory which contains artifacts that are not compatible with the current CPU.
This results in a very confusing errors like missing required CPU features: "EnumSet(AVX512DQ | AVX512VL | AVX512F)"', lib/wasix/tests/runners.rs:75:21 .

The module cache implementation should either check the artifact features for support, or somehow include the cpu features in the cache path. Note: the latter is quite tricky to do in a sensible way that doesn't require lots of cache lookups.

Related to #4187

[theduke]

Nothing needed anymore.