Remove TfGrain.

PiperOrigin-RevId: 707422138

connectomics/jax/checkpoint.py

@@ -22,7 +22,6 @@
 from etils import epath
 import flax
 import grain.python as grain
-import grain.tensorflow as tfgrain
 from orbax import checkpoint as ocp
 import tensorflow as tf
 
@@ -118,14 +117,3 @@ def restore_checkpoint(
   return manager.restore(
       manager.latest_step() if step is None else step,
       args=ocp.args.Composite(**restore_args_dict))
-
-
-TfGrainCheckpointHandler = tfgrain.OrbaxCheckpointHandler
-
-
-@ocp.args.register_with_handler(  # pytype:disable=wrong-arg-types
-    TfGrainCheckpointHandler, for_save=True, for_restore=True
-)
-@dataclasses.dataclass
-class TfGrainCheckpointArgs(ocp.args.CheckpointArgs):
-  item: Any