⬆️ (deps): Update pyo3 requirement from 0.20.3 to 0.21.1

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@v0.20.3...v0.21.1)

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

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

Cargo.toml

@@ -10,7 +10,7 @@ name = "pillow_jxl"
 crate-type = ["cdylib"]
 
 [dependencies]
-pyo3 = { version="0.20.3", features = ["extension-module"] }
+pyo3 = { version="0.21.1", features = ["extension-module"] }
 jpegxl-rs = { path="./jpegxl-rs/jpegxl-rs", default-features = false, features = ["threads"] }
 
 [features]