Switch test code to PyQt6

tests/test_formats/test_fmt_tokenizer.py

@@ -22,7 +22,7 @@ from __future__ import annotations
 
 import pytest
 
-from PyQt5.QtGui import QFont
+from PyQt6.QtGui import QFont
 
 from novelwriter import CONFIG
 from novelwriter.constants import nwHeadFmt, nwStyles

tests/test_formats/test_fmt_toodt.py

@@ -27,7 +27,7 @@ from shutil import copyfile
 
 import pytest
 
-from PyQt5.QtGui import QColor
+from PyQt6.QtGui import QColor
 
 from novelwriter.common import xmlIndent
 from novelwriter.constants import nwHeadFmt

tests/test_formats/test_fmt_toqdoc.py

@@ -22,7 +22,7 @@ from __future__ import annotations
 
 import pytest
 
-from PyQt5.QtGui import QFont, QTextBlock, QTextCharFormat, QTextCursor
+from PyQt6.QtGui import QFont, QTextBlock, QTextCharFormat, QTextCursor
 
 from novelwriter import CONFIG
 from novelwriter.constants import nwUnicode