⬆️ Update pyo3 requirement from 0.19.2 to 0.21.2 (#4)

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

Author: dependabot[bot]

Cargo.toml

@@ -14,7 +14,7 @@ license = "MIT"
 anyhow = "1.0.82"
 toml = "0.8.12"
 insta = { version = "1.38.0", features = ["yaml"] }
-pyo3 = "0.19.2"
+pyo3 = "0.21.2"
 quote = "1.0.36"
 serde = { version = "1.0.198", features = ["derive"] }
 serde_json = "1.0.116"