[RSDK-5823] Remove unused Board.Attributes code (#501)

This should have been removed in #491, but I forgot. It's dead code. Grepping the codebase for `Attributes` turns up only 1 result (in src/viam/errors.py), and that's a false positive.

Linking things up: I noticed this while reviewing viamrobotics/docs#2313

Author: penguinland

src/viam/components/board/board.py

@@ -1,5 +1,4 @@
 import abc
-from dataclasses import dataclass
 from datetime import timedelta
 from multiprocessing import Queue
 from typing import Any, Callable, Dict, Final, List, Optional
@@ -25,13 +24,6 @@ class Board(ComponentBase):
 
     SUBTYPE: Final = Subtype(RESOURCE_NAMESPACE_RDK, RESOURCE_TYPE_COMPONENT, "board")
 
-    @dataclass
-    class Attributes:
-        remote: bool
-        """
-        Indicates whether this board is accessed over a remote connection, e.g. gRPC.
-        """
-
     class AnalogReader(ComponentBase):
         """
         AnalogReader represents an analog pin reader that resides on a Board.