[cmake] only require a CXX compiler when tests are build

[ThomasDevoogdt]

No description provided.

[ThomasDevoogdt]

@Cyan4973 any chance that this gets merged?

[Cyan4973]

Some cmake tests are failing following this cmake PR.
It should be investigated.

[ThomasDevoogdt]

@Cyan4973 I updated the patch, but I can't really test it properly.

[Cyan4973]

It still fails, mostly the same way.

If you don't have local testing capabilities,
you can still enable Github Actions CI tests directly within your fork,
so that they run automatically in your fork after each commit,
thus making you autonomous from upstream test infrastructure, which features additional security constraints.

[ThomasDevoogdt]

It still fails, mostly the same way.

If you don't have local testing capabilities, you can still enable Github Actions CI tests directly within your fork, so that they run automatically in your fork after each commit, thus making you autonomous from upstream test infrastructure, which features additional security constraints.

I was not really able to get those runners working. But I have the feeling (or I hope so), that the third time will be the good time.