[PRQ#49842] Deletion Request for lib32-libgit2

MarsSeed [1] filed a deletion request for lib32-libgit2 [2]: See deletion requests PRQ#49840 for lib32-libheif, and PRQ#49841 for lib32-rav1e to see why they shouldn't exist on AUR. Safe to clean up this unneeded library as well after the former ones. [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/lib32-libgit2/