Allowed keys for DocConfig.
Required because DocConfig uses skip_serializing_if = "Option::is_none" on some fields
(repository, path), whose defaults are None and thus excluded from serialization.
Allowed keys for SymbolicConfig.
Required because some compatibility aliases and empty length collections are skipped by default
serialization, but they are still valid user-facing config keys.
Allowed keys for VyperConfig.
Required because VyperConfig uses skip_serializing_if = "Option::is_none" on all fields,
causing the default serialization to produce an empty dict.