BLD: Clean up dependencies for Cython files
- [ ] closes #xxxx
- [ ] tests added / passed
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry

an does this solve the problem?
this is including way too many things; all of the pyx are not needed just the pxd FFS I asked exactly that pyx vs pxd question over in #18089 and you guys ignored it.  "Fix" this yourselves.

As far as I'm concerned this makes things distinctly worse. IMO, let's focus on getting a working build first.  We can "clean up" later in subsequent commits to this PR.  Mixing the two together is making it hard for us to make progress here. Actually, due to merge conflicts, this will be annoying to merge in as written.  Let's start from scratch.