Update clu to use inspect.get_annotations(cls) oveer cls.__annotations__

PiperOrigin-RevId: 723027214

clu/metrics.py

@@ -57,6 +57,7 @@ def evaluate(variables_p, test_ds):
 """
 from __future__ import annotations
 from collections.abc import Mapping, Sequence
+import inspect
 from typing import Any, TypeVar, Protocol
 
 from absl import logging
@@ -536,7 +537,8 @@ def empty(cls: type[C]) -> C:
         _reduction_counter=_ReductionCounter(jnp.array(1, dtype=jnp.int32)),
         **{
             metric_name: metric.empty()
-            for metric_name, metric in cls.__annotations__.items()
+            for metric_name, metric
+            in inspect.get_annotations(cls, eval_str=True).items()
         })
 
   @classmethod
@@ -546,7 +548,8 @@ def _from_model_output(cls: type[C], **kwargs) -> C:
         _reduction_counter=_ReductionCounter(jnp.array(1, dtype=jnp.int32)),
         **{
             metric_name: metric.from_model_output(**kwargs)
-            for metric_name, metric in cls.__annotations__.items()
+            for metric_name, metric
+            in inspect.get_annotations(cls, eval_str=True).items()
         })
 
   @classmethod