cancel-in-progress wrongly implemented

[SimonRit]

I am sorry but it seems that #98 and #99 have messed up the CI of remote modules (e.g. RTK). I think that the problem is that when combining .github/workflows/build-test-cxx.yml and .github/workflows/build-test-package-python.yml in a single file (as in https://github.com/RTKConsortium/RTK/blob/master/.github/workflows/build-test-package.yml), one of the two (the first one I guess) is cancelled. I don't see a solution for this, maybe we should just revert the two commits and implement cancel-in-progress) in the module files instead?
Sorry for the trouble...

[dzenanz]

We should act quickly, then. Do you want to propose another solution, or just revert the existing change?

[SimonRit]

I have tried a few things but failed. I think this is the same issue as actions/runner#3205. I'll prepare two PRs to revert, you can merge unless someone wants to pitch in.