Iris and Iris.X4 should use the common CI settings

[saki7]

In iris-cpp/x4#29, we split common configurations into separate YAML files. The configuration scheme is very well designed and should be applied to Iris too.

I think it's better to move those configuration files to this repository and reference ours from X4.

[saki7]

Additionally, we should remove the branch-specific cache in a cleanup step.

See: https://docs.github.com/en/actions/how-tos/manage-workflow-runs/manage-caches#force-deleting-cache-entries