Textual backend raising log messages on app exit

[freakboy3742]

Describe the bug

Oberved in #3299 (comment)

If you run an example app under the textual backend, using Textual 3.0, exiting the app seems to generate some Textual logging messages on the console.

Steps to reproduce

1. Run tutorial 1 under the Textual backend, using Textual 3.1
2. Close the app
3. See message in console:

focus was removed
Unmount() >>> TogaApp(title='Tutorial 1', classes={'-dark-mode'}, pseudo_classes={'dark', 'focus'}) method=None

Expected behavior

A cleanly exiting app should not generate log messages.

Screenshots

No response

Environment

• Operating System:
• Python version:
• Software versions:
  • Briefcase:
  • Toga:
  • ...

Logs

Additional context

No response