build(deps): update pyo3 requirement from 0.19 to 0.20 (#44)

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

Cargo.toml

@@ -19,7 +19,7 @@ crate-type = ["cdylib"]
 [dependencies]
 age-core = "0.9"
 age = { version = "0.9", features = ["ssh"] }
-pyo3 = { version = "0.19", features = [
+pyo3 = { version = "0.20", features = [
     "extension-module",
     "abi3",
     "abi3-py38",