Saved Hotbars Dissapear when Loading a world in 23w44a

Put the summary of the bug you're having here

What I expected to happen was...:
My Saved Hotbars from Previous Versions should've saved when Loading 23w44a

What actually happened was...:
Any and All Saved Hotbars are gone when loading a world into 23w44a

Steps to Reproduce:
1. Load a World in 23w43b
2. Create a Saved Hotbar using m+1, etc

3. Load that same world in 23w44a

4. That Hotbar should now be missing