License clarification needed in README.rst file

### Things to check first

- [x] I have searched the existing issues and didn't find my bug already reported there

- [x] I have checked that my bug is still present in the latest release

### Exceptiongroup version

1.3.0

### Python version

3.13.6

### What happened?

I am packaging this module in Fedora and as part of package review, I got this question about licensing.
May I know if this python module is dual licensed that is MIT and PSF-2.0? or some files are in MIT and some in PSF-2.0 license?
Can we have some information added in README.rst about this license clarification?
Thanks

### How can we reproduce the bug?

No detailed license information available in README.rst file.