These changes are also true for PySide6.

1. OpenGL classes have been moved to a separate PyQt6.QtOpenGL namespace:

PyQt5:

from PyQt5.QtGui import (QOpenGLBuffer, QOpenGLShader, QOpenGLShaderProgram,
                        QOpenGLTexture)

PyQt6:

from PyQt6.QtOpenGL import (QOpenGLBuffer, QOpenGLShader, …