Update file stale-issues.yml
Please don't use "update <file>" commit messages. These make it harder to understand at a glance at commit history what the changes are.

https://cbea.ms/git-commit/
In this PR: 
1) Increased the no. of operations per run from 30 to 1000 to pick more issues and PRs.
2) Add Override stale . 
3) Prevent to remove stale label when issue PRs update.
4) Changed the version of stale from v5 to v7. 