bump minimum zig version to 0.15.1
Update minimum_zig_version from 0.14.0 to 0.15.1 to reflect the
actual Zig version required for building the library with the
current codebase changes.
Amp-Thread-ID: https://ampcode.com/threads/T-d7d30501-29b2-4efe-a39a-200167bdf876
Co-authored-by: Amp <amp@ampcode.com>