Fix PyO3 0.25.x compatibility issues

- Update lib.rs module function signature for new Bound API
- Replace .to_owned() with .unbind() for PyArray returns
- Downgrade ndarray from 0.16.1 to 0.15.6 to match numpy 0.25.0 requirement
- Resolve version conflicts between direct and transitive dependencies

All compilation errors resolved, maturin build now successful

Author: saleh-mir

Cargo.toml

@@ -11,7 +11,7 @@ crate-type = ["cdylib"]
 [dependencies]
 pyo3 = { version = "0.25.1", features = ["extension-module"] }
 numpy = "0.25.0"
-ndarray = "0.16.1"
+ndarray = "0.15.6"
 
 # Optimize for size and performance in release builds
 [profile.release]