Get rid of abseil warnings

tests/tensorflow-notebook/units/unit_tensorflow.py

@@ -1,6 +1,13 @@
 # Copyright (c) Jupyter Development Team.
 # Distributed under the terms of the Modified BSD License.
+import os
+
 import tensorflow as tf
 
+# Suppress logging warnings
+# https://stackoverflow.com/a/78803598
+os.environ["GRPC_VERBOSITY"] = "ERROR"
+os.environ["GLOG_minloglevel"] = "2"
+
 print(tf.constant("Hello, TensorFlow"))
 print(tf.reduce_sum(tf.random.normal([1000, 1000])))