Support a new `Durability::NEVER_CHANGE`#1035

ChayimFriedman2 wants to merge 2 commits intosalsa-rs:mastersalsa-rs/salsa:masterfrom

ChayimFriedman2:never-change-durability-v3ChayimFriedman2/salsa:never-change-durability-v3Copy head branch name to clipboard