The key name of the test instances field that represents the namespaced ID of the test environment is different from the changelog

The Bug

According to the source code decompiled with official mapping, there is a "batch" field in the TestData.CODEC instead of the "environment" field in the 25w03a changelog.
It causes the "environment" field not to work.

Relates to MC-279518.

Steps to reproduce:

1. Try to load the following datapack in a new world.
2. Close the game and check the log.

Find Errors in The Log:

Caused by: java.lang.IllegalStateException: No key batch in MapLike[{"type":"minecraft:block_based","environment":"bug:empty","structure":"minecraft:empty","max_ticks":20}]