[CI] Close stall PRs immediately after marking them stall (#310)

Author: aobolensk

.github/workflows/nightly.yml

@@ -18,7 +18,7 @@ jobs:
           stale-pr-message: 'This pull request is stale for 2 weeks and is going to be closed'
           days-before-pr-stale: 14
           days-before-issue-stale: -1
-          days-before-pr-close: 14
+          days-before-pr-close: 0
           days-before-issue-close: -1
           stale-pr-label: 'stale'
           operations-per-run: 100