Update Arabic (ar_SA) language pack to v2 (#440)

Point the ar_SA entries at the v2 release asset, which adds U+20C1
SAUDI RIYAL SIGN (Unicode 17.0) to the pack's ten Gothic extension
fonts. The glyph outline comes from Noto Naskh Arabic (SIL OFL 1.1),
scaled to Vazirmatn's digit height; nothing else in the pack changes
and the v1 asset stays published. id and version follow the existing
<locale>_v<n> naming. Tested on a Core Time 2.

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>