Upgrade python 3.7 to 3.8 in sync github action

[arpit-jn]

Changes

• Upgrade python version from 3.7 to 3.8 in sync github action, as sync is about to deprecate that github action

References

• https://updates.snyk.io/final-reminder-on-snyk-cli-images-and-snyk-images-containing-eol-software-297657
• https://docs.snyk.io/scm-ide-and-ci-cd-integrations/snyk-ci-cd-integrations/eol-policy-snyk-images/images-no-longer-supported-by-snyk

Testing

• [ ] This change adds unit test coverage
• [ ] This change adds integration test coverage
• [ ] This change has been tested on the latest version of the platform/language or why not

Checklist

• [ ] I have read the Auth0 general contribution guidelines
• [ ] I have read the Auth0 Code of Conduct
• [ ] All existing and new tests complete without errors