Deprecation warning from `CodeWidget`

[siddhantwahal]

CodeWidget emits the following deprecation warning:

/path/to/venv/pyface/ui/qt/code_editor/code_widget.py:91: UserWarning: 
The "+" operator is deprecated in Qt For Python 6.0 .
Please use "|" instead.
  QtCore.Qt.Modifier.SHIFT + QtCore.Qt.Key.Key_Backtab
/path/to/venv/pyface/ui/qt/code_editor/code_widget.py:94: UserWarning: 
The "+" operator is deprecated in Qt For Python 6.0 .
Please use "|" instead.
  QtCore.Qt.Modifier.CTRL + QtCore.Qt.Key.Key_Slash

The "+" operator is being used to hook up a key sequence here:

pyface/pyface/ui/qt/code_editor/code_widget.py

Lines 90 to 95 in d654883

	self.unindent_key = QtGui.QKeySequence(
	QtCore.Qt.Modifier.SHIFT + QtCore.Qt.Key.Key_Backtab
	)
	self.comment_key = QtGui.QKeySequence(
	QtCore.Qt.Modifier.CTRL + QtCore.Qt.Key.Key_Slash
	)