Phayriosis Reborn - Phase 3: static meteor worldgen removal

Purpose
- Disable the old large/small meteors that appeared as ordinary chunk world generation.
- Preserve all meteor blocks, structures, configured/placed features, and Java feature classes for later live falling-meteor work.

Implementation
- Removed only these Forge biome modifier datapack entries:
  * data/phayriosisreborn/forge/biome_modifier/large_meteor_biome_modifier.json
  * data/phayriosisreborn/forge/biome_modifier/small_meteor_biome_modifier.json
- The configured_feature and placed_feature JSONs remain intentionally. Without a biome modifier attaching them to overworld biome generation, they do not naturally generate.
- LargeMeteorFeature.class, SmallMeteorFeature.class, meteorphase1-2.nbt, meteorsmall.nbt, meteor dungeon structures, and meteor blocks remain untouched.
- No runtime infection behavior, commands, Phase 2 world settings, or machine GUIs were changed.

Validation
- Confirmed the only datapack references that attach phayriosisreborn:large_meteor and phayriosisreborn:small_meteor to biomes were the two removed biome modifiers.
- Jar integrity verified after rewrite.

Continuation
- Phase 4 should build the server-side meteor event scheduler/eligibility system. Do not restore the removed biome modifiers.
- Superflat is sufficient for startup/world creation regression testing, but static terrain worldgen absence must be checked in a fresh normal terrain world.
