Update PyO3 dependency and document wheel rationale

Rely on explicit abi3-py310 flag for ABI3 compatibility in the
PyO3 dependency feature set while retaining extension-module
enabled. Document the rationale for free-threaded 3.13/3.14 wheels
alongside ABI3 wheel guidance in the release notes.

Author: kosiew

Cargo.toml

@@ -50,7 +50,6 @@ tokio = { version = "1.47", features = [
 ] }
 pyo3 = { version = "0.26", features = [
     "extension-module",
-    "abi3",
     "abi3-py310",
 ] }
 pyo3-async-runtimes = { version = "0.26", features = ["tokio-runtime"] }

dev/release/README.md

@@ -130,6 +130,10 @@ datafusion-22.0.0-cp37-abi3-manylinux_2_17_x86_64.manylinux2014_x86_64.whl
 datafusion-22.0.0-cp37-abi3-win_amd64.whl
 ```
 
+Note: PyO3's free-threaded CPython builds (3.13t/3.14t) use a distinct ABI and ignore the `abi3` setting. We keep
+the `abi3-py310` feature enabled to preserve the stable-ABI wheels for GIL-enabled Python, and we additionally ship
+version-specific `cp313t`/`cp314t` wheels for the free-threaded builds.
+
 Upload the wheels to testpypi.
 
 ```bash