No, they don't. At least nothing IDE specific. Most languages come with a way to configure dependencies and build configuration independently from IDEs. If your IDE is incapable of picking those up, your IDE is crap. If you want to keep your developers from having to muck about with IDE settings, put those settings into an independent repo. If your IDE is incapable of picking up configuration from a specific directory, again, your IDE is crap.

Does your CI read IDE settings or language specific settings? If you're depending on IDE specific settings in your pipeline, your entire pipeline is brittle.

So, no "sufficiently complex project" should need any IDE specific config in the project repo.