Ensure more explicit system ordering for preparing view target. (#15000)

Fixes #14993 (maybe). Adds a system ordering constraint that was missed
in the refactor in #14833. The theory here is that the single threaded
forces a topology that causes the prepare system to run before
`prepare_windows` in a way that causes issues. For whatever reason, this
appears to be unlikely when multi-threading is enabled.

crates/bevy_render/src/view/mod.rs

@@ -123,7 +123,8 @@ impl Plugin for ViewPlugin {
  (
  prepare_view_attachments
  .in_set(RenderSet::ManageViews)
- .before(prepare_view_targets),
+ .before(prepare_view_targets)
+ .after(prepare_windows),
  prepare_view_targets
  .in_set(RenderSet::ManageViews)
  .after(prepare_windows)