Handle InvalidStateError during termination when using `run_in_termin…

…al`/`patch_stdout`. (#1926)

In some edge cases, during cancellation, probably when using anyio, we can get
this `InvalidStateError` during termination. This patch fixes that bug.

```
Traceback (most recent call last):
  File "/home/jonathan/git/python-prompt-toolkit/src/prompt_toolkit/application/run_in_terminal.py", line 49, in run
    async with in_terminal(render_cli_done=render_cli_done):
  File "/home/jonathan/.local/share/uv/python/cpython-3.11.10-linux-aarch64-gnu/lib/python3.11/contextlib.py", line 217, in __aexit__
    await anext(self.gen)
  File "/home/jonathan/git/python-prompt-toolkit/src/prompt_toolkit/application/run_in_terminal.py", line 114, in in_terminal
    new_run_in_terminal_f.set_result(None)
asyncio.exceptions.InvalidStateError: invalid state
```

src/prompt_toolkit/application/run_in_terminal.py

@@ -111,4 +111,7 @@ async def f():
             app._request_absolute_cursor_position()
             app._redraw()
         finally:
-            new_run_in_terminal_f.set_result(None)
+            # (Check for `.done()`, because it can be that this future was
+            # cancelled.)
+            if not new_run_in_terminal_f.done():
+                new_run_in_terminal_f.set_result(None)