Turns out Arch Linux doesn't officially support aarch64 architecture, so we will drop if from this AUR build process.
Changes:
- drop aarch64 from PKGBUILD, .SRCINFO, and AUR validation workflow
- keep AUR process aligned with official Arch Linux x86_64 support
- install rust directly in CI to avoid Arch cargo provider prompts
- fetch sources before running cargo audit and audit inside the
fetched repo
- disable makepkg LTO for this package to avoid Arch packaging link
failures
- mark /etc/numa.toml as a backup file
- Add local AUR build scratch directory exclusion to .gitignore