Improvement: Exclude feature PR from auto-closing

[nicu1989]

Since we implemented the auto-close of stale PRs: #1029 we got a request to implement a mechanism of excluding feature PRs from auto-closing: #890 (comment)

[AlexanderLanin]

Hey @FScholPer, should feature requests just stay open indefinitely? I'm afraid no-one will bother closing them. How about a longer timeframe? e.g. 60 or 90 days instead of 30?

[AlexanderLanin]

(Removing feature request, as that's probably a reserved type)

[FScholPer]

I would be okay with 90 days as this should be more than enough. How about the others @eclipse-score/automotive-score-technical-leads ?

[nicu1989]

@FScholPer, @eclipse-score/automotive-score-technical-leads should we go ahead with 90 days?