docs: fix version list creation for dropdown

[erisu]

Motivation and Context

Correct doc version dropdown list display

Description

Added logic to ensure that similar major version, e.g. 12.x and 12.x-2025.01, are distinct from each other and that the version drop down list display accordingly.

Testing

build and ran docs locally.

Checklist

• I've run the tests to see all new and existing tests pass
• I added automated test coverage as appropriate for this change
• Commit is prefixed with (platform) if this change only applies to one platform (e.g. (android))
• If this Pull Request resolves an issue, I linked to the issue in the text above (and used the correct keyword to close issues using keywords)
• I've updated the documentation if necessary