VK_EXT_dynamic_rendering_unused_attachments is required for correct working.
Renderdoc hides this extension, but most platforms do work. However the
Windows Intel driver crashes when using iGPUs; they don't support this
extension at all.
This change does a more strict extension test so drivers that do not
support this extension will fallback to OpenGL. When using renderdoc it
is now allowed to compile blender with `WITH_RENDERDOC=On`.
Future developments are needed to add support for Intel iGPUs on
Windows.
Pull Request: https://projects.blender.org/blender/blender/pulls/128986