Improve Kestra Github + Dockerhub release flow

[danlsgiga]

Feature description

Sorry for opening a feature request that is not related to the product itself.

I've been running Kestra to routinely check for newer latest versions of itself and once that happens I open a PR against my repo to get Kestra updated by our CI.
The thing is, your repo CI is tagging even older hotfix releases as latest... for example, right now the latest version is v0.20.13 but v0.19.18 is tagged as latest in the repo.
I can easily add a check in my flow to check if the latest version is higher than the previous one, however, I think tagging latest to the most recent builds causes a lot of confusion.

I'm running on v0.20.13 and getting PRs to "upgrade" to v0.19.18 is causing some confusion 😅

Along with that, I've noticed that Docker images sometimes take a really long time to be pushed to Dockerhub after a release, which caused some issues for us already when tried to upgrade a day after the release and the image was not in Dockerhub yet.

Generally speaking, I can check dockerhub directly before opening a PR in my repo instead of Github, but the timing between github release and dockerhub image push is sometimes a bit too long.

Appreciate if improvements are made in these scenarios! 🙌🏻