Make 3.x match 3.x-dev in case there is no stable release yet

[lazka]

Current situation: We will get 3.11 in about a month and I want to test it to CI from now on.

This means I now have to use 3.11-dev and in one month downgrade to 3.11 to get the stable release from then on.

Ideally 3.11 would match 3.11-dev as long as there exists no stable release yet for that version, unless I'm missing something.

I know it's possible to do 3.11.0-alpha - 3.11.0 but that still would require me to clean things up eventually and I'd like to add it once and never touch it again.

[EwoutH]

Yes, this would be a great feature. I support this!

[vsafonkin]

Hi @lazka, thank you for your help, we will take a look at this.

[mayeut]

This is #414

[brcrista]

Let's consolidate on #213 since that's been around for a while and has more people following it.