Add in "stable" and "oldstable"

[Jacalz]

Just the stable input. I don't understand what stable adds for actions/setup-go. If you only want stable builds you can set go-version accordingly. If there is good use case for stable, it can be added.

The README mentions that stable hasn't been added. I believe it would be very good to add it because it means that the workflow file can be the same without having to create a new commit (plus PR depending on the project). The same goes for using oldstable for the older maintained release. Using these two makes it possible to basically have a fire-and-forget workflow that constantly keeps updated to test with the latest supported Go versions.

This goes hand in hand with my issue over at setup-go: actions/setup-go#450

[WillAbides]

Thanks for bringing this up. You can already simulate stable by setting go-version: 1.x, but I don't think there is a way to simulate oldstable. Your use case seems valid, and there doesn't seem to be a downside, so I'm inclined to add this. I'll be looking at it today, but I can't be sure when a PR will land.

As an aside, the part of the README you quoted is referencing the "stable" input as it existed in actions/setup-go@v2. v3 dropped that input and replaced it with the stable and oldstable aliases.

[WillAbides]

This is released in v1.14.0

[Jacalz]

Thanks :)