vulkan: Migrate shader module hash to BLAKE3.

vulkan: Migrate shader module hash to BLAKE3.

Shaders are the largest thing we hash now, so they benefit from a faster
hash.

Change the field name from `sha1` to `hash` to avoid tying the definition
to a particular algorithm. This doubles down as a precaution against
callers still assuming a 20-byte hash (in which case the compilation will
error out).

Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22571>