Blender 3.5 has a performance regression in the image engine
that made the image engine 3-4x slower then 3.4. The cause of
this was the new way how panning was implemented.
This PR disables the new panning for now as a short term fix.
In the future the panning and improvements we did ensured
better performance when dealing with higher resolution images.
But the regression for regular images weren't acceptable.
This fix might introduce other performance regressions on
lower end systems.
In the future we still want to improve the performance to
get back to Blender 3.0 performance, but that requires more
work and has a different priority.
Pull Request: #106803
Jeroen Bakker