Address a PySide6 incompatibility with QTextEdit

[hmaarrfk]

• Tested against Conda-forge
• Tested against pypi -- actually pypi doesn't recreate this... 6.8.0.1 does, but the recently released 6.8.0.2 does not.

Closes jupyter/qtconsole#624

Output from conda-forge test when the patch isnt' applied.

============================================ test session starts =============================================
platform linux -- Python 3.10.14, pytest-8.3.3, pluggy-1.5.0 -- /home/mark/miniforge3/envs/dev/bin/python3.10
cachedir: .pytest_cache
PySide6 6.8.0 -- Qt runtime 6.8.0 -- Qt compiled 6.8.0

PyQt5: not installed
PySide2: not installed
PyQt6: not installed
PySide6: PySide: 6.8.0 - Qt: 6.8.0

rootdir: /home/mark/git/qtpy
configfile: pytest.ini
plugins: timeout-2.3.1, xdist-3.6.1, time-machine-2.16.0, forked-1.6.0, anyio-4.6.2.post1, qt-4.4.0, env-1.1.5, cov-5.0.0
collected 16 items

qtpy/tests/test_qtwidgets.py::test_qtextedit_functions FAILED                                          [  6%]

================================================== FAILURES ==================================================
__________________________________________ test_qtextedit_functions __________________________________________

qtbot = <pytestqt.qtbot.QtBot object at 0x714cd78a6020>
pdf_writer = (<PySide6.QtGui.QPdfWriter(0x57c8c8e05790) at 0x714cd78e9e00>, PosixPath('test.pdf'))

    def test_qtextedit_functions(qtbot, pdf_writer):
        """Test functions mapping for QtWidgets.QTextEdit."""
        assert QtWidgets.QTextEdit.setTabStopWidth
        assert QtWidgets.QTextEdit.tabStopWidth
        assert QtWidgets.QTextEdit.print_
        textedit_widget = QtWidgets.QTextEdit(None)
        textedit_widget.setTabStopWidth(90)
        assert textedit_widget.tabStopWidth() == 90
        print_device, output_path = pdf_writer
        textedit_widget.print_(print_device)
        assert output_path.exists()
        # https://github.com/jupyter/qtconsole/issues/624
        assert QtWidgets.QTextEdit.setExtraSelections
>       textedit_widget.setExtraSelections([])
E       AttributeError: type object 'PySide6.QtWidgets.QTextEdit' has no attribute 'ExtraSelection'. Did you mean: 'extraSelections'?

qtpy/tests/test_qtwidgets.py:35: AttributeError
-------------------------------------------- Captured Qt messages --------------------------------------------
QtWarningMsg: Could not find the Qt platform plugin "wayland" in ""
============================================ slowest 10 durations ============================================
0.15s setup    qtpy/tests/test_qtwidgets.py::test_qtextedit_functions
0.04s call     qtpy/tests/test_qtwidgets.py::test_qtextedit_functions
0.00s teardown qtpy/tests/test_qtwidgets.py::test_qtextedit_functions
========================================== short test summary info ===========================================
FAILED qtpy/tests/test_qtwidgets.py::test_qtextedit_functions - AttributeError: type object 'PySide6.QtWidgets.QTextEdit' has no attribute 'ExtraSelection'. Did you mean: 'extraSelections'?
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! stopping after 1 failures !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
============================================= 1 failed in 0.56s ==============================================

[coveralls]

coverage: 89.967% (-0.2%) from 90.18%
when pulling 0cc4165 on hmaarrfk:fix_pyside680
into 2cc5fc4 on spyder-ide:master.

[hmaarrfk]

I see that they released the source files for 6.8.0.2. I'll see if i can rebuild for conda-forge and close this PR and the original issue.

[hmaarrfk]

conda-forge/pyside2-feedstock#251

[hmaarrfk]

Things seem to be resolved in PySide6 6.8.0.2