Prevent out of date release pipelines

Problem

The indexer release scheduled pipeline open an MR that currently must be merged rather quickly. When new commits are merged after the release MR, the release notes won’t be up to date.

Note: Out of date CHANGELOG are eventually corrected during the next release because the automated script will update it.

Proposals

We discussed the following proposals

• Have a bot approve/merge it if the pipelines are green
  • Issue with this: the danger-review pipeline currently fails when run by the bot. It's been difficult to fix
• Create a new pipeline that fails if it’s not run against current main branch tag
• Put SHA in changelog file and compare to last commit from main branch and if those differ it fails

The easiest will likely be a failing pipeline in .gitlab-ci.yml if the SHA from the pipeline MR isn't up to date