Bump pyo3 from 0.20.2 to 0.20.3 in /src/rust (#10462) (#10465)

Bumps [pyo3](https://github.com/pyo3/pyo3) from 0.20.2 to 0.20.3.
- [Release notes](https://github.com/pyo3/pyo3/releases)
- [Changelog](https://github.com/PyO3/pyo3/blob/v0.20.3/CHANGELOG.md)
- [Commits](PyO3/pyo3@v0.20.2...v0.20.3)

---
updated-dependencies:
- dependency-name: pyo3
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: reaperhulk