Updates for Maturin 1.8: add a version key in the project metadata

[agriyakhetarpal]

Description

Through PyO3/maturin#2391 via the recently released https://github.com/PyO3/maturin/releases/tag/v1.8.0, we've been seeing failing builds for PyXIRR in Pyodide (logs), which was added in pyodide/pyodide#4513.

I've opened this PR since I saw that you were listed as a maintainer for PyXIRR's recipe in Pyodide, and I shall be applying this PR as a patch to fix the failing build. If you'd like me to set it as a dynamic attribute or something else of your liking, please let me know. Thank you!

Additional context

• List of changes for Maturin 1.8.0: https://github.com/PyO3/maturin/blob/main/Changelog.md#180

[agriyakhetarpal]

I don't think any other changes should be required here; triggering https://github.com/Anexen/pyxirr/actions/runs/12546123566 would be helpful and I could take a look if there are any failures.

[Anexen]

Closing this because I've added dynamic = ["version"] to the project section since maturin is automatically pulling the version from Cargo.toml.

[agriyakhetarpal]

Thanks! That should work, too. :)