dev/release: do not close self when pruning old issues
Created by: bobheadxi
e.g. https://github.com/sourcegraph/sourcegraph/issues/25167#issuecomment-923983382 closed itself :(
Created by: bobheadxi
e.g. https://github.com/sourcegraph/sourcegraph/issues/25167#issuecomment-923983382 closed itself :(