Undead mobs no longer burn in sunlight in biomes without rain while it's raining

Undead mobs no longer burn in daylight when they are in biomes without precipitation or with snowfall while it is raining.

How to reproduce

1. Go to biome without rain (e.g. a desert), or go to a snowy biome

2. Make sure it's daytime

3. /weather rain

4. Use a spawn egg to spawn a zombie

5. ❌ The zombie catches fire

Expected result

The zombie should only be protected from fire when in a biome where it rains