Bump pyo3 to 0.28.1

Update Cargo.toml to use pyo3 = 0.28.1 (keeping the "extension-module" feature) and regenerate Cargo.lock to reflect the updated pyo3-related dependencies.

Author: JR-1991

Cargo.lock

@@ -29,7 +29,7 @@ colored = "3.0.0"
 convert_case = "0.8.0"
 toml = "0.9.5"
 textwrap = "0.16.1"
-pyo3 = { version = "0.26.0", features = ["extension-module"], optional = true }
+pyo3 = { version = "0.28.1", features = ["extension-module"], optional = true }
 openai-api-rs = { version = "6.0.6", optional = true }
 wasm-bindgen = { version = "0.2.95", optional = true }
 serde-wasm-bindgen = { version = "0.6.5", optional = true }