QOpenGLWidget initialization significantly slower than QGLWidget when using multisampling with NVIDIA on Linux

While upgrading our application from Qt 5.15 to Qt 6.9 we noticed a significant performance regression between the deprecated QGLWidget and the QOpenGLWidget.

In our application we create several widgets for OpenGL rendering to render multiple different scenes. These use MSAAx8 by default. 
Initializing the widgets for the first time takes significantly longer with the QOpenGLWidget than it did using the QGLWidget.

We could reduce the issue down to a [Minimal Reproducible Example|https://gitlab.com/thorwin.vogt/minimalreproducableexampleqopenglissue,] which creates 6 QOpenGLWidgets which create a single MSAAx8 framebuffer on initialization. This is roughly equivalent to the use case in our application. The sample count also directly affects the initialization time.

We verified this issue on Qt 5.15, Qt 6.8 and Qt 6.9 on multiple devices using different versions of Ubuntu and using NVIDIA GPU.

We could not verify the issue on Windows 11 and Windows 11 using WSL 2.

We could not verify the issue using an AMD GPU, in our case the RX 7800 XT on Ubuntu 22.04.5 LTS.

Attached is output from profiling the minimal reproducible example with perf ran through clion.