feat(aarch64): remove awkernel_aarch64; move content to awkernel_lib - #768

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: technote-space/assign-author@9558557c5c4816f38bd06176fbc324ba14bb3160. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/