chore(deps): Update pyo3 requirement from 0.19.0 to 0.20.0

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@v0.19.0...v0.20.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

Cargo.toml

@@ -25,7 +25,7 @@ path = "src/lib.rs"
 [dependencies]
 thiserror = "1.0.28"
 portgraph = { version = "0.9.0", features = ["serde", "petgraph"] }
-pyo3 = { version = "0.19.0", optional = true, features = [
+pyo3 = { version = "0.20.0", optional = true, features = [
     "multiple-pymethods",
 ] }
 regex = "1.9.5"