The "Bucket of Axolotl" entity cannot be retextured based on axolotl colour

the log entries for the errors are as such:
[01:05:14] [Worker-Main-1/ERROR]: {citresewn} Errored while parsing CIT: NBT condition is not supported since 1.21 @L4 in minecraft:optifine/cit/items/axolotl_bucket/axolotl_bucket_blue.properties from file/Kizzcraft_1.21
[01:05:14] [Worker-Main-1/ERROR]: {citresewn} Errored while parsing CIT: NBT condition is not supported since 1.21 @L4 in minecraft:optifine/cit/items/axolotl_bucket/axolotl_bucket_cyan.properties from file/Kizzcraft_1.21
[01:05:14] [Worker-Main-1/ERROR]: {citresewn} Errored while parsing CIT: NBT condition is not supported since 1.21 @L4 in minecraft:optifine/cit/items/axolotl_bucket/axolotl_bucket_gold.properties from file/Kizzcraft_1.21
[01:05:14] [Worker-Main-1/ERROR]: {citresewn} Errored while parsing CIT: NBT condition is not supported since 1.21 @L4 in minecraft:optifine/cit/items/axolotl_bucket/axolotl_bucket_lucy.properties from file/Kizzcraft_1.21
[01:05:14] [Worker-Main-1/ERROR]: {citresewn} Errored while parsing CIT: NBT condition is not supported since 1.21 @L4 in minecraft:optifine/cit/items/axolotl_bucket/axolotl_bucket_wild.properties from file/Kizzcraft_1.21

This is specifically for the following property:

type=item
items=axolotl_bucket
texture=axolotl_bucket_blue
****** nbt.Variant=4 ******

• I have attached the latest.log file relevant to this issue
• I have checked the issues and have not found an existing case of this issue
• I am using the latest version of CIT Resewn for my version of minecraft
• I am using the mod on Fabric Loader
• I have disabled broken paths in the mod's config and the issue persists

As the error says, nbt.Variant is just not a thing in 1.21.
You need to use the new component check for axolotl buckets, specifically minecraft:bucket_entity_data.