remove unneeded annotation import (tinygrad#8934)

Author: chenyuxyz

tinygrad/codegen/rewriter.py

@@ -1,4 +1,3 @@
-from __future__ import annotations
 from typing import Optional, Any, Callable
 import functools, itertools, operator
 from collections import defaultdict

tinygrad/engine/multi.py

@@ -1,4 +1,3 @@
-from __future__ import annotations
 import functools, itertools, operator
 from tinygrad.helpers import all_same, all_int, dedup, prod, DEBUG, RING, getenv
 from tinygrad.ops import Ops, UOp, sint