Gently nudge project managers to update default GitLab, when relevant

Problem/Motivation

For some projects, the Official Release version on drupal.org, and Default GitLab dev-version is out of sync.

For example, the official release here on drupal.org could be version 3, but the GitLab default version could be an old 8.x-1.0, not updated for years.

This can be problematic when creating MR's, since the target branch will be the old 8.x-1.0 branch, and not as intended, the new version's dev branch (3.x-dev).

Steps to reproduce

Create an MR, changing just a single line, and get a huge diff, due to the target branch being incorrect.

Proposed resolution

Perhaps the project version management UI could be improved with a strategically well placed help text, like "Remember to match the default GitLab dev-version with the latest release." or something like that?

I guess tackling this challenge will also be relevant, even after moving issues to GitLab?

Remaining tasks

User interface changes

API changes

Data model changes