zfs: merge openzfs/zfs@508fff0e4 (zfs-2.1-release) into stable/13

Notable upstream pull request merges:

#12253 module/zfs: simplify ddt_stat_add() loop
#12280 Help compiller optimize out abd_verify()
#12288 Avoid 64bit division in multilist index functions

Obtained from: OpenZFS
OpenZFS commit: 508fff0e4b0653744fd6ae7857cc860e4d0d80af
OpenZFS tag: zfs-2.1.0-rc8