TF SAM memory reduction (#23732)

* Extremely small change to TF SAM dummies to reduce memory usage on build

* remove debug breakpoint

* Debug print statement to track array sizes

* More debug shape printing

* More debug shape printing

* Now remove the debug shape printing

* make fixup

* make fixup

src/transformers/models/sam/modeling_tf_sam.py

@@ -1155,7 +1155,7 @@ class TFSamPreTrainedModel(TFPreTrainedModel):
         """
         VISION_DUMMY_INPUTS = tf.random.uniform(
             shape=(
-                3,
+                1,
                 self.config.vision_config.num_channels,
                 self.config.vision_config.image_size,
                 self.config.vision_config.image_size,