Allow Vector Pass with Motion Blur enabled

As far as I know, it is technically possible to render the Vector Pass while Motion Blur is enabled, but currently it is disabled by design.

I believe we should have the option to enable it even with Motion Blur turned on. The Vector Pass is not only useful for post-processing motion blur, but it is also essential for temporal denoising and other advanced workflows.

For example, I am using the Turbo Tools add-on, which can perform temporal denoising when the Vector Pass is available. However, as soon as Motion Blur is enabled, this feature becomes unavailable. Having access to Vector Pass in this situation would make it possible to stabilize renders more effectively, especially when using heavy effects such as Motion Blur and Depth of Field.

Right now, these effects tend to produce a lot of flickering, even with high render settings, and I’m forced to rely on other denoising methods that are less accurate. Allowing Vector Pass output alongside Motion Blur would solve this issue and significantly improve denoising workflows.