THIS IS A DATAPACK! You need to either add it to your world's datapack folder or use an automatic loader such as OpenLoader or Paxi.
This datapack disables the Hardening Catalyst on items that may break balance heavily, such as Bewitchment's Death Protection Poppets, Gilded Armor from MC Dungeons Armors, etc.
How to install?
Download the zip and put it in your world's datapacks folder.
Alternatively, install openloader or paxi, and put the datapack inside their data folder.