Deleted project still stays visible and 404 issue

Deleted project still remains visible and issues with 404 when clicking on it

@joshfng time was added to handle NFS slowness.

@yorickpeterse can we add where(pending_delete: false) as default scope for Project model without performance impact?

@dzaporozhets If the column is indexed I don't think that should be a problem.

Then lets do it. @DouweM please propose milestone

Added ~12980 label

Added ~155950 label

Milestone changed to 8.7

Reassigned to @zj

Started branch deleted-project-still-stays-visible-and-404-issue-14138

mentioned in merge request !3439 (merged)

Status changed to closed by merge request !3439 (merged)

mentioned in commit 3cd28c01