Unfortunately, it's easier to change what we distribute, except that has _always_ been "include" (based on a 2.4 installer I had laying around). And of course we can't change the repo.

Still, case sensitivity is becoming more acceptable on Windows and there are more ways to enable it, so we're probably best to deal with this. For 3.10, we can update PC/layout/main.py and tools/msi/common.wxs#L80 to create "Include", and we probably want to go over the few places where we may reference it to make sure the case is consistent. (Noting that distutils is fully deprecated in 3.10, so it doesn't matter.)

I'm not sure that it qualifies as enough of a bugfix for 3.8 or 3.9.1, so I think we'll leave them alone. A case-sensitive file system can easily support a symlink/junction from "Include" to "include" anyway, which is a pretty straightforward workaround ;)