fix(config): Serialize hex bytes to hex string

src/gallia/command/config.py

@@ -19,7 +19,7 @@
     get_args,
 )
 
-from pydantic import BeforeValidator
+from pydantic import BeforeValidator, PlainSerializer
 from pydantic.fields import _FromFieldInfoInputs
 from pydantic_core import PydanticUndefined
 
@@ -65,6 +65,7 @@ def err_int(x: str, base: int) -> int:
 HexBytes = Annotated[
     bytes,
     BeforeValidator(lambda x: x if isinstance(x, bytes) else binascii.unhexlify(x)),
+    PlainSerializer(lambda x: binascii.hexlify(x)),
 ]
 """
 Special type for a field, which parses bytes from hex strings.