docs(general): Update Python versions and add env vars to the docs

[tsmithv11]

User description

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

Description

Update supported Python versions and add environment variables to the docs.

Partial fix for #6805

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my feature, policy, or fix is effective and works
• New and existing tests pass locally with my changes