chore(python): add support for python 3.11 (#306)

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Post-Processor: gcr.io/cloud-devrel-public-resources/owlbot-python:latest@sha256:c43f1d918bcf817d337aa29ff833439494a158a0831508fda4ec75dc4c0d0320

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

scheduler/snippets/noxfile.py

@@ -88,7 +88,7 @@ def get_pytest_env_vars() -> Dict[str, str]:
 
 # DO NOT EDIT - automatically generated.
 # All versions used to test samples.
-ALL_VERSIONS = ["3.7", "3.8", "3.9", "3.10"]
+ALL_VERSIONS = ["3.7", "3.8", "3.9", "3.10", "3.11"]
 
 # Any default versions that should be ignored.
 IGNORED_VERSIONS = TEST_CONFIG["ignored_versions"]