Fix typos in the Lib directory (GH-28775)

Fix typos in the Lib directory as identified by codespell.

Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>

Lib/test/test_asyncio/test_streams.py

@@ -711,7 +711,7 @@ class StreamTests(test_utils.TestCase):
         # See asyncio issue 168.  This test is derived from the example
         # subprocess_attach_read_pipe.py, but we configure the
         # StreamReader's limit so that twice it is less than the size
-        # of the data writter.  Also we must explicitly attach a child
+        # of the data writer.  Also we must explicitly attach a child
         # watcher to the event loop.
 
         code = """\

Lib/test/test_asyncio/test_subprocess.py

@@ -228,7 +228,7 @@ class SubprocessMixin:
         # buffer large enough to feed the whole pipe buffer
         large_data = b'x' * support.PIPE_MAX_SIZE
 
-        # the program ends before the stdin can be feeded
+        # the program ends before the stdin can be fed
         proc = self.loop.run_until_complete(
             asyncio.create_subprocess_exec(
                 sys.executable, '-c', 'pass',

Lib/test/test_asyncio/test_tasks.py

@@ -3269,7 +3269,7 @@ class RunCoroutineThreadsafeTests(test_utils.TestCase):
             self.assertTrue(task.done())
 
     def test_run_coroutine_threadsafe_task_cancelled(self):
-        """Test coroutine submission from a tread to an event loop
+        """Test coroutine submission from a thread to an event loop
         when the task is cancelled."""
         callback = lambda: self.target(cancel=True)
         future = self.loop.run_in_executor(None, callback)
@@ -3277,7 +3277,7 @@ class RunCoroutineThreadsafeTests(test_utils.TestCase):
             self.loop.run_until_complete(future)
 
     def test_run_coroutine_threadsafe_task_factory_exception(self):
-        """Test coroutine submission from a tread to an event loop
+        """Test coroutine submission from a thread to an event loop
         when the task factory raise an exception."""
 
         def task_factory(loop, coro):