Fix #27722
Fix #27357
Fix #25837
1. Fix the typo `BlockingByDependenciesNotPermitted`, which causes the
`not permitted message` not to show. The correct one is `Blocking` or
`BlockedBy`
2. Rewrite the perm check. The perm check uses a very tricky way to
avoid duplicate checks for a slice of issues, which is confusing. In
fact, it's also the reason causing the bug. It uses `lastRepoID` and
`lastPerm` to avoid duplicate checks, but forgets to assign the
`lastPerm` at the end of the code block. So I rewrote this to avoid this
trick.
3. It also reuses the `blocks` slice, which is even more confusing. So I
rewrote this too.
9b59af37e7