Don't require the `RenderShadowLodOrigin` resource to be present when rendering. (#24359)

PR #24289 introduced the `RenderShadowLodOrigin` resource, which is used
to construct the `View` GPU resource. Because shadow maps are a PBR
concept, that resource is only constructed if the PBR plugin is present.
But we share the `View` structure between the 2D and 3D paths. Thus,
when constructing the `View` structure, we should gracefully handle the
potential absence of the `RenderShadowLodOrigin` resource. This PR does
that.

Closes #24352.