BUG: Safe app window close

[larsoner]

Follow-up to #127 which should help with this:

E   pytest.PytestUnraisableExceptionWarning: Exception ignored in: <function BackgroundPlotter.__del__ at 0x7f869d7a9ab0>
E   
E   Traceback (most recent call last):
E     File "/opt/hostedtoolcache/Python/3.10.9/x64/lib/python3.10/site-packages/pyvistaqt/plotting.py", line 741, in __del__
E       self.app_window.close()
E   RuntimeError: wrapped C/C++ object of type _MNEMainWindow has been deleted

Makes the code more DRY at the same time rather than duplicating the logic, as self.close() is already just:

        if not self._closed:
            # Can get:
            #
            #     RuntimeError: wrapped C/C++ object of type MainWindow has
            #     been deleted
            #
            # So let's be safe and try/except this in case of a problem.
            try:
                self.app_window.close()
            except Exception:  # pragma: no cover # pylint: disable=broad-except
                pass

[codecov]

Codecov Report

Merging #258 (bd75225) into main (9df3c4b) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #258   +/-   ##
=======================================
  Coverage   97.22%   97.22%           
=======================================
  Files           8        8           
  Lines         648      648           
  Branches       90       81    -9     
=======================================
  Hits          630      630           
  Partials       18       18           

[larsoner]

This is a pretty straightforward fix and includes some CI fixes that should hopefully allow us to merge some of the dependabot PRs, so I'll mark this for merge-when-green