You really like villager heal when it sleep in bedrock and want it to be in java edition? Take this

Healthy-Villager

A nerfed version of bedrock edition healing

Healing villager a small amount when they wake up

Notes

Configurable using command /function Healthy_Villager:heal with {"strength":<amplifier>,"duration":<seconds>} Villager will be healed if they wake up at dawn, the datapack checks once in 0-400 tick and apply 5 second of regeneration 2

Performance

it will create a small lag when it checks if you have a potatoes device

How to install:

Drag the zip files into datapacks gui when creating world or navigate to <your world name>/world/datapacks and put there, then go to your world/server and use /datapack enable "Healthy_Villager-datapack-1.21+.zip"