Bump support package revisions; add 3.14 support package.

[freakboy3742]

• Update the support package for 3.9-3.13 to a version that uses the new package-site structure.
• Add an initial 3.14 support package.

This doesn't enable CI testing for 3.14 because of an issue with httpcore (encode/httpcore#995); that prevents the CI environment from downloading the support package (or doing anything else involving httpx).

PR Checklist:

• All new features have been tested
• All new features have been documented
• I have read the CONTRIBUTING.md file
• I will abide by the code of conduct