Modernize Python typing across the codebase

Automated via ruff UP006, UP007, UP035, UP045 rules (target: py311):

- Replace `typing.List`, `Dict`, `Tuple`, `Set`, `FrozenSet`, `Type`
  with their built-in equivalents (`list`, `dict`, `tuple`, etc.)
- Replace `typing.Optional[X]` with `X | None`
- Replace `typing.Union[X, Y]` with `X | Y`
- Move `Mapping`, `Sequence`, `Callable`, `Awaitable`,
  `MutableMapping`, `MutableSequence`, `Iterator`, `AsyncIterator`,
  `AsyncGenerator` imports from `typing` to `collections.abc`
- Remove now-unused `typing` imports
- Add `from __future__ import annotations` to 5 files that use
  forward-reference strings in `X | "Y"` annotations

tests/test_pipeline.py

@@ -289,7 +289,7 @@ class TestPipelineTask(unittest.IsolatedAsyncioTestCase):
                 task.run(PipelineTaskParams(loop=asyncio.get_event_loop())),
                 timeout=1.0,
             )
-        except asyncio.TimeoutError:
+        except TimeoutError:
             pass
 
         assert upstream_received
@@ -317,7 +317,7 @@ class TestPipelineTask(unittest.IsolatedAsyncioTestCase):
                 task.run(PipelineTaskParams(loop=asyncio.get_event_loop())),
                 timeout=1.0,
             )
-        except asyncio.TimeoutError:
+        except TimeoutError:
             pass
 
         assert upstream_received
@@ -346,7 +346,7 @@ class TestPipelineTask(unittest.IsolatedAsyncioTestCase):
                 task.run(PipelineTaskParams(loop=asyncio.get_event_loop())),
                 timeout=1.0,
             )
-        except asyncio.TimeoutError:
+        except TimeoutError:
             pass
 
         assert "First" in upstream_texts
@@ -382,7 +382,7 @@ class TestPipelineTask(unittest.IsolatedAsyncioTestCase):
                 task.run(PipelineTaskParams(loop=asyncio.get_event_loop())),
                 timeout=1.0,
             )
-        except asyncio.TimeoutError:
+        except TimeoutError:
             pass
         assert heartbeats_counter == expected_heartbeats
 
@@ -417,7 +417,7 @@ class TestPipelineTask(unittest.IsolatedAsyncioTestCase):
                     task.run(PipelineTaskParams(loop=asyncio.get_event_loop())),
                     timeout=0.6,
                 )
-            except asyncio.TimeoutError:
+            except TimeoutError:
                 pass
 
             log_text = log_output.getvalue()
@@ -441,7 +441,7 @@ class TestPipelineTask(unittest.IsolatedAsyncioTestCase):
                 task.run(PipelineTaskParams(loop=asyncio.get_event_loop())),
                 timeout=0.3,
             )
-        except asyncio.TimeoutError:
+        except TimeoutError:
             assert True
         else:
             assert False