cppwarningnotifier is needed

[saki7]

This warning was not caught on X4's recent CI: https://github.com/iris-cpp/x4/actions/runs/22108561063/job/63898308067#step:6:74

[saki7]

This task requires cppwarningnotifier's maintainer (@yaito3014) to adjust it to make it capable of handling Iris's current CI settings.

So #33 is going to be the blocker.