PYSEC-2026-1009 Missing validation causes denial of service via `UnsortedSegmentJoin`

Impact The implementation of tf.rawops.UnsortedSegmentJoin does not fully validate the input arguments. This results in a CHECK-failure which can be used to trigger a denial of service attack: python import tensorflow as tf tf.rawops.UnsortedSegmentJoin inputs=tf.constant"this", shape=12,...