fixing category slot definiton

[puja-trivedi]

Current:

• adding pattern requirement to category slot. this adds a field_validator in pydantic to check the value assigned to category follow a specific pattern. We are hard-coding the pattern to be ^bican:[A-Z][A-Za-z]+$. This will cause an error for classes that are inherited from models defined outside of bican i.e. biolink.

Solution:

• remove pattern. there is no reason for category to be validated since the value is not assigned from input data.
• remove bican_biolink_edit completely. Since we are now modifiying the range of category directly in the jsonld context, I don't think we need to change the range in the yaml from uriorcurie to curie since they both get translated to str in pydantic
• same fix but for schemasheets. Need to merge this PR
• close this PR, I don't think we need to use pattern