Sometimes "spawn_target" is ignored in datapacks

If a datapack alters the "spawn_target" field in data\minecraft\worldgen\noise_settings\overworld.json, sometimes this field is ignored and spawn is placed in an unsuitable location.

To reproduce:

1. Create a new world with seed 2.
2. Include the attached datapack "BDM68's Continent Pack 1.20.4.zip".
3. Create world -> spawn is in the middle of the ocean, with "continentalness" outside the values specified in the spawn_target field in the datapack.

The attached datapack modifies the "continentalness" values for all Overworld biomes, which makes oceans cover about 70% of the map. It also adjusts the data\minecraft\worldgen\noise\continentalness.json file so land masses have the same size as a Large Biomes world. To cater for the larger oceans, the spawn_target field has the continentalness parameter altered to 0.324348.

Some seeds that appear to work correctly are 3 and 4.