Added PyQt6 support

Tests/test_imageqt.py

@@ -14,7 +14,9 @@ def test_rgb():
     # typedef QRgb
     # An ARGB quadruplet on the format #AARRGGBB,
     # equivalent to an unsigned int.
-    if ImageQt.qt_version == "side6":
+    if ImageQt.qt_version == "6":
+        from PyQt6.QtGui import qRgb
+    elif ImageQt.qt_version == "side6":
         from PySide6.QtGui import qRgb
     elif ImageQt.qt_version == "5":
         from PyQt5.QtGui import qRgb

Tests/test_qt_image_qapplication.py

@@ -7,7 +7,9 @@
 if ImageQt.qt_is_installed:
     from PIL.ImageQt import QPixmap
 
-    if ImageQt.qt_version == "side6":
+    if ImageQt.qt_version == "6":
+        from PyQt6.QtWidgets import QApplication, QHBoxLayout, QLabel, QWidget
+    elif ImageQt.qt_version == "side6":
         from PySide6.QtWidgets import QApplication, QHBoxLayout, QLabel, QWidget
     elif ImageQt.qt_version == "5":
         from PyQt5.QtWidgets import QApplication, QHBoxLayout, QLabel, QWidget

src/PIL/ImageQt.py

@@ -23,6 +23,7 @@
 from ._util import isPath
 
 qt_versions = [
+    ["6", "PyQt6"],
     ["side6", "PySide6"],
     ["5", "PyQt5"],
     ["side2", "PySide2"],
@@ -32,7 +33,12 @@
 qt_versions.sort(key=lambda qt_version: qt_version[1] in sys.modules, reverse=True)
 for qt_version, qt_module in qt_versions:
     try:
-        if qt_module == "PySide6":
+        if qt_module == "PyQt6":
+            from PyQt6.QtCore import QBuffer
+            from PyQt6.QtCore.QIODevice import OpenMode as QIODevice
+            from PyQt6.QtGui import QPixmap, qRgba
+            from PyQt6.QtGui.QImage import Format as QImage
+        elif qt_module == "PySide6":
             from PySide6.QtCore import QBuffer, QIODevice
             from PySide6.QtGui import QImage, QPixmap, qRgba
         elif qt_module == "PyQt5":