chore(deps): update dependency pandas to v1.4.2 (#751)

* chore(deps): update dependency pandas to v1.4.2

* revert pin change for py37; use === to prevent updates for environment specific pins

Co-authored-by: Anthonios Partheniou <partheniou@google.com>

Author: renovate-bot

storage/samples/snippets/requirements.txt

@@ -1,4 +1,4 @@
 google-cloud-pubsub==2.11.0
 google-cloud-storage==2.2.1
-pandas==1.3.5; python_version == '3.7'
-pandas==1.4.0; python_version >= '3.8'
+pandas===1.3.5; python_version == '3.7'
+pandas==1.4.2; python_version >= '3.8'