End crystal and TNT explosions do same damage regardless of difficulty

The Bug:
End crystals do the same damage across difficulties in 1.19.3. This also applies to TNT explosions.
This is what the damage looks like when you stand in the middle of one:

1.19.2 and previous versions:
Peaceful: 0 hp / 0 full hearts
Easy: 43.5 hp/ 21.75 full hearts
Normal: 85 hp / 42.5 full hearts
Hard: 127.5 hp / 63.75 full hearts

1.19.3:
Peaceful: 85 hp / 42.5 full hearts
Easy: 85 hp / 42.5hp full hearts
Normal: 85 hp / 42.5 hp full hearts
Hard: 85 hp / 42.5 hp full hearts 

Steps to reproduce:

1. Set the difficulty to anything other than normal, such as hard, peaceful, or easy.
2. Spawn an end crystal.
3. Observe that the end crystal does the same damage as it would on normal difficulty.

Expected behavior:
The damage from an end crystal should do the same as on version 1.19.2 and before that.

Actual behavior:
The same damage that end crystals do on normal difficulty is the same as on other difficulties.

Code analysis:
Code analysis by etch can be found in this comment.