Prevent destroy invalid member migrations from running

What does this MR do and why?

Describe in detail what your merge request does and why.

db/post_migrate/20220809002011_schedule_destroy_invalid_group_members.rb and spec/migrations/20220901035725_schedule_destroy_invalid_project_members_spec.rb tried to scan too many rows which hit a statement timeout limit

Incident: gitlab-com/gl-infra/production#7779 (closed) Comment with explanation: #365028 (comment 1108954620)

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.