Update pyo3 requirement from 0.17.0 to 0.20.0 (#10)

Updates the requirements on [pyo3](https://github.com/pyo3/pyo3) to permit the latest version.
- [Release notes](https://github.com/pyo3/pyo3/releases)
- [Changelog](https://github.com/PyO3/pyo3/blob/main/CHANGELOG.md)
- [Commits](PyO3/pyo3@v0.17.0...v0.20.0)

---
updated-dependencies:
- dependency-name: pyo3
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Cargo.toml

@@ -9,4 +9,4 @@ name = "rust_python_extension"
 crate-type = ["cdylib"]
 
 [dependencies]
-pyo3 = { version = "0.17.0", features = ["extension-module"] }
+pyo3 = { version = "0.20.0", features = ["extension-module"] }