GH-7: [Python] Fix invalid-context-manager error (#30)

* Add py.typed file to signify that the library is typed

See the relevant PEP https://peps.python.org/pep-0561

* Prepare `pyarrow-stubs` for history merging

MINOR: [Python] Prepare `pyarrow-stubs` for history merging

Co-authored-by: ZhengYu, Xu <zen-xu@outlook.com>

* Add `ty` configuration and suppress error codes

* One line per rule

* Add licence header from original repo for all `.pyi` files

* Revert "Add licence header from original repo for all `.pyi` files"

This reverts commit 1631f39.

* Prepare for licence merging

* Exclude `stubs` from `rat` test

* Add Apache licence clause to `py.typed`

* Reduce list

* Add `ty` as a step in the action

* Run in the correct directory

* Remove `check` from `pip`

* Fix `unresolved-reference` error

* Revert "Fix `unresolved-reference` error"

This reverts commit 7ee3d2f.

* Fix invalid-context-manager

---------

Co-authored-by: Patrick J. Roddy <patrickjamesroddy@gmail.com>

Author: rok

python/pyarrow/tests/test_flight.py

@@ -49,8 +49,14 @@
         ClientMiddleware, ClientMiddlewareFactory,
     )
 except ImportError:
+    class context_like(object):
+        def __enter__(self):
+            return self
+        def __exit__(self, exc_type, exc_value, traceback):
+            pass
+
     flight = None
-    FlightClient, FlightServerBase = object, object
+    FlightClient, FlightServerBase = context_like, context_like
     ServerAuthHandler, ClientAuthHandler = object, object
     ServerMiddleware, ServerMiddlewareFactory = object, object
     ClientMiddleware, ClientMiddlewareFactory = object, object