Close inactive issue workflow

[phymbert]

we have more than 1k opened issues. It can be confusing for end users to understand what is obsolete or real issue.

@ggerganov if you agree, we can create a simple github workflow:

https://docs.github.com/en/actions/managing-issues-and-pull-requests/closing-inactive-issues

[ggerganov]

Yes, seems like a good idea. Let's add it

[phymbert]

Implemented in:

• issues: ci - close inactive issue with workflow #6053