Add new CI to cover uncommon configurations, running weekly

[mvieth]

See issue #5101
If you prefer a name other than "Ubuntu variety", feel free to make suggestions.

[larshg]

Is it run whenever there is changes to master and every Saturday?
Or is it only master when changes in the paths specified?

It looks nice🥳

And the todo's can be added/adjusted after a test period?
Ie. other dependencies and tutorials.

[mvieth]

Is it run whenever there is changes to master and every Saturday? Or is it only master when changes in the paths specified?

It is the same behaviour as the Docker build: it runs every Saturday, and when there are changes in the paths (master branch and prs)

It looks nice:partying_face:

Thanks 😄

And the todo's can be added/adjusted after a test period? Ie. other dependencies and tutorials.

Yes exactly. I think the most important stuff is already covered (different compilers, C++ standards, build types, ...), but there is of course a lot more we can test. I think it is worth to already have this basic version running soon, instead of trying to implement all possible ideas in this PR

[Hanooona]

E