Spyder is stuck on PyQt5 for the foreseeable future, so for the sake of our installers and moving forward with modern, updated Qt mne-installers just transitioned to qt6-main (and it's not a great idea to have both PyQt5 and PySide6/PyQt6 installed simultaneously). So for 1.8 we should update the installation instructions to point people to the Spyder standalone installers:

https://docs.spyder-ide.org/current/installation.html#standalone-installers

And mention how to then configure Spyder to use the MNE-Python installation's Python / kernels (which should be pretty easy via the GUI), or possibly supply some script to do it.