Investigate deprecated Pydantic Field argument

[ytausch]

Comment:

We currently set deprecated as argument for Pydantic fields, which raises the following warning:

PydanticDeprecatedSince20: Using extra keyword arguments on `Field` is deprecated and will be removed. Use `json_schema_extra` instead. (Extra keys: 'deprecated'). Deprecated in Pydantic V2.0 to be removed in V3.0. See Pydantic V2 Migration Guide at https://errors.pydantic.dev/2.6/migration/

Also, Pydantic adds a deprecated option (with the same name!) probably in 2.7: #1756 (comment)

This should be investigated.