This data pack is an alternative to the mod that I maintain.
1.21.5 is only confirmed to work for that version. It may work for subsequent versions, but I'll try and keep an up-to-date list of versions. It may lag with Minecraft's releases.
It shares zombie curing gossips across the server. You do need to right click a villager twice to get the effect due to the limitations of data packs. If you see a particle effect, it means you need to click off the villager because the gossip value has changed. If there's no particles, it means it's already applied (or there is no gossip to apply).
This data pack shares only the major positive gossip (the zombie curing gossip). This means trades may still differ if you, for example, punch a villager. There is a cooldown, however, so trades should return to the same over time.