Remove duplicate import of 'all_of' in test file

Removed duplicate import of 'all_of' from hamcrest.

Author: nikitagrover19

sdks/python/apache_beam/io/gcp/pubsub_integration_test.py

@@ -26,6 +26,8 @@
 import uuid
 
 import pytest
+from hamcrest.core.core.allof import all_of
+
 from apache_beam.io.gcp import pubsub_it_pipeline
 from apache_beam.io.gcp.pubsub import PubsubMessage
 from apache_beam.io.gcp.pubsub import WriteToPubSub
@@ -34,7 +36,7 @@
 from apache_beam.testing import test_utils
 from apache_beam.testing.pipeline_verifiers import PipelineStateMatcher
 from apache_beam.testing.test_pipeline import TestPipeline
-from hamcrest.core.core.allof import all_of
+
 
 INPUT_TOPIC = 'psit_topic_input'
 OUTPUT_TOPIC = 'psit_topic_output'