chore: upgrade pyo3 to 0.27 (from 0.26)

[vigith]

Migration Guide https://pyo3.rs/v0.27.0/migration.html

• lifetime changes
• explicit conversion to PyErr
• downcast is deprecated

(pynumaflow-lite) ➜  pynumaflow-lite git:(pyo3-upgrade) ✗ make test
maturin develop
🍹 Building a mixed python/rust project
🔗 Found pyo3 bindings
🐍 Found CPython 3.13 at /Users/vigith/code/git/numaproj/numaflow-python/packages/pynumaflow-lite/.venv/bin/python
📡 Using build options features from pyproject.toml
   Compiling pynumaflow-lite v0.1.0 (/Users/vigith/code/git/numaproj/numaflow-python/packages/pynumaflow-lite)
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.85s
📦 Built wheel for CPython 3.13 to /var/folders/9v/ztc8jgrn1b9dvwd5sv1z0ndh0000gp/T/.tmpQ1lWW0/pynumaflow_lite-0.1.0-cp313-cp313-macosx_11_0_arm64.whl
✏️ Setting installed package as editable
🛠 Installed pynumaflow-lite-0.1.0
pytest -v
================================================================================================= test session starts =================================================================================================
platform darwin -- Python 3.13.2, pytest-8.4.2, pluggy-1.6.0 -- /Users/vigith/code/git/numaproj/numaflow-python/packages/pynumaflow-lite/.venv/bin/python3
cachedir: .pytest_cache
rootdir: /Users/vigith/code/git/numaproj/numaflow-python/packages/pynumaflow-lite
configfile: pyproject.toml
collected 13 items

tests/test_accumulator.py::test_python_accumulator_server_and_rust_client[accumulator_stream_sorter.py] PASSED                                                                                                  [  7%]
tests/test_batchmap.py::test_python_batch_server_and_rust_client[batchmap_cat.py] PASSED                                                                                                                        [ 15%]
tests/test_batchmap.py::test_python_batch_server_and_rust_client[batchmap_cat_class.py] PASSED                                                                                                                  [ 23%]
tests/test_map.py::test_python_server_and_rust_client[map_cat.py] PASSED                                                                                                                                        [ 30%]
tests/test_map.py::test_python_server_and_rust_client[map_cat_class.py] PASSED                                                                                                                                  [ 38%]
tests/test_mapstream.py::test_python_stream_server_and_rust_client[mapstream_cat.py] PASSED                                                                                                                     [ 46%]
tests/test_mapstream.py::test_python_stream_server_and_rust_client[mapstream_cat_class.py] PASSED                                                                                                               [ 53%]
tests/test_reduce.py::test_python_reduce_server_and_rust_client[reduce_counter_class.py] PASSED                                                                                                                 [ 61%]
tests/test_reduce.py::test_python_reduce_server_and_rust_client[reduce_counter_func.py] PASSED                                                                                                                  [ 69%]
tests/test_session_reduce.py::test_python_session_reduce_server_and_rust_client[session_reduce_counter_class.py] PASSED                                                                                         [ 76%]
tests/test_sink.py::test_python_sink_server_and_rust_client[sink_log.py] PASSED                                                                                                                                 [ 84%]
tests/test_sink.py::test_python_sink_server_and_rust_client[sink_log_class.py] PASSED                                                                                                                           [ 92%]
tests/test_source.py::test_python_source_server_and_rust_client[source_simple.py] PASSED                                                                                                                        [100%]

================================================================================================= 13 passed in 42.63s =================================================================================================```

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.85%. Comparing base (b0c7e7b) to head (03caeb3).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #286   +/-   ##
=======================================
  Coverage   93.85%   93.85%           
=======================================
  Files          66       66           
  Lines        3009     3009           
  Branches      155      155           
=======================================
  Hits         2824     2824           
  Misses        135      135           
  Partials       50       50           

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[vigith]

lifetime changes are due we supporting 3.14 which can optionally not use Python GIL

The two lifetimes are separate:
'a can be shorter than 'py (borrow from temporary input)
'a can be longer than 'py (borrow data that outlives the Python attachment)