Update rules_python to 0.31.0

Failed in 34s
:ubuntu: Ubuntu 18.04 LTS (OpenJDK 11, gcc 7.5.0)curl -sS https://raw.githubusercontent.com/bazelbuild/continuous-integration/master/buildkite/bazelci.py?1711015045 -o bazelci.py && python3.6 bazelci.py runner --task=ubuntu1804
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Ran in 10s
:mac: macOScurl -sS https://raw.githubusercontent.com/bazelbuild/continuous-integration/master/buildkite/bazelci.py?1711015045 -o bazelci.py && python3 bazelci.py runner --task=macos
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Ran in 19s
Total Job Run Time: 35s