All-red LOC diff PRs: logical candidate for bot auto-approvals

[ariskataoka]

Given that a PR to be scanned;
When it contains removed lines only;
Then the vip-go-ci bot should provide a different message than the regular comment (provided by the option post-generic-pr-support-comments-string )

Docs.: https://github.com/Automattic/vip-go-ci#general-support-messages

Eg.:

The PR with the modifications displayed above received the comment found in the option post-generic-pr-support-comments-string. A specific comment would give more clarity about what the PR owner can do after receiving that message.