ci/cd: Get rid of race condition

[JasonYao]

Info

• Back with the change in 8bfea51, one of the changes was adding in a matrix of supported python versions, namely 3.6 and 3.7
• However, now that we have two environments, there is now a race condition in the deploy step, where both try to upload.
• Now this isn't that big of an issue, since if it already finds that it exists, then it gracefully exits, but it'd still be a good thing to only do a release on one environment.
• Recommendation is to do it on the 3.7 one, or at least a 3.7 one