`default_dripstone_particle` still re-injected into dimension_type JSON on 1.21.11 (latest 3.9.2) → registry parse failure, server won't boot (ref #1240)

[nickynice1]

Problem

On Minecraft 1.21.11, Iris re-generates dimension_type JSON files under datapacks/iris/data/iris/dimension_type/*.json that contain:

"minecraft:visual/default_dripstone_particle": {"value": "minecraft:dripstone_drip_water_lava"}

Minecraft 1.21.11's registry codec cannot parse this field:

No key type in MapLike[{"value":"minecraft:dripstone_drip_water_lava"}]

→ the datapack fails to load → the server refuses to start (Failed to load datapacks, can't proceed with server load).

This was already reported in #1240 (closed) for environment: NETHER on 3.9.1. It is still present in the latest release 3.9.2 and, in our case, affects the generated dimension_type files of a custom Iris dimension in general.

Crucially, Iris re-injects the invalid field on every boot, so a one-time manual edit is not enough — we currently have to strip minecraft:visual/default_dripstone_particle from every generated dimension_type JSON in a pre-start wrapper script, otherwise the server crashes on the next boot.

Environment

• Iris: 3.9.2-1.20.1-1.21.11 (latest release)
• Server: Paper 1.21.11

Steps to reproduce

1. Run Iris 3.9.2 on Paper 1.21.11 with an Iris dimension.
2. Let Iris generate / regenerate its datapack dimension_type JSONs.
3. Restart → server fails to load datapacks with the No key type in MapLike error on the dripstone field.

Suggested fix

Don't emit minecraft:visual/default_dripstone_particle in generated dimension_type JSON on 1.21.11, or emit it in the shape the 1.21.11 registry codec accepts (the current {"value": ...} form is rejected).

Related: #1240