Use workflow templates

[tomkerkhove]

Describe the current behavior
Multiple workflows have a "Build & run devcontainer image" that has to be kept in sync. We are tracking these things in a comment but this can cause issues when not kept in sync.

Describe the improvement
Instead of duplicating it, we should refactor the workflows to use reusable workflows to centralize the logic of it.

Additional context
I am happy to take a stab at this when I have some spare time.

[tomkerkhove]

Feel free to assign to me

[matthchr]

This still seems like a good idea, but not a high priority currently. We'll get to it when we have time

[theunrepentantgeek]

No change from above.

[matthchr]

It'd be nice to do this, but it's not urgent.

[tomkerkhove]

I forgot about this and started looking in to it, but since I have opened the issue the scope has increased and looks like they're all similar but also not similar so not sure if it's still beneficial.