ci(github/ci.yaml): re-use dev build across jobs for tests

[petermetz]

Description

This is more of an idea rather than a well defined task at this point (at the time of this writing).

The idea is that - as part of the build-dev CI job, we could package that state of the repo (with the build artifacts) as a container and then use that for the rest of the jobs which would all just fetch the image and then run the tests it's supposed to within it.
Currently the configure script takes 7 minutes for each job on average (8 if we turn off the GitHub Action caching so it doesn't help much).
The idea is that if we can download and launch the container with the built artifacts baked into it, in a fraction of this 7 minutes, then we can eliminate a lot of the time the CI jobs take and also reduce CPU cycles needed for it to run in general.

Acceptance Criteria

1. CI is faster than it was
2. The dev container image is used for the builds/test execution so that we have a higher chance of finding out about issues with that as well and in general make the dev container more reliable

For this to work, we need the dev container stability improvements done first =>
Depends on #2404

[github-actions]

This PR/issue depends on:

• fix(vscode/devcontainer): unexpected exit stdout /etc/passwd #2404
  By Dependent Issues (🤖). Happy coding!