BLD: GH30873 Workaround parallel build failures
Fix parallel build race conditions due to the same source files being
used in multiple targets.  To workaround the distutils bug, create
unique .c files for each target that just #include the original file.

- [x] closes #30873 
- [ ] tests added / passed
- [ ] Ensure all linting tests pass, see [here](https://pandas.pydata.org/pandas-docs/dev/development/contributing.html#code-standards) for how to run them
- [ ] whatsnew entry
