stop pinning pyo3

Fixes #4.

Previously we were pinning a specific version, because the latest
release had a bug that led to failing tests. Now it's been fixed.

Author: oconnor663

Cargo.toml

@@ -19,6 +19,6 @@ crate-type = ["cdylib"]
 
 [dependencies]
 blake3 = { version = "0.3.0", features = ["rayon"] }
-pyo3 = { version = "=0.9.0-alpha.1", features = ["extension-module"] }
+pyo3 = { version = "0.9.2", features = ["extension-module"] }
 arrayref = "0.3.6"
 hex = "0.4.2"