Fix pbr example text rotation (#19571)

# Objective This example migration was missed in #16615 https://pixel-eagle.com/project/b25a040a-a980-4602-b90c-d480ab84076d/run/10633/compare/10627?screenshot=3D+Rendering/pbr.png ## Solution Use new `UiTransform` ## Testing `cargo run --example pbr`

Author: rparrett

examples/3d/pbr.rs

@@ -85,8 +85,8 @@ fn setup(
  right: Val::ZERO,
  ..default()
  },
- Transform {
- rotation: Quat::from_rotation_z(std::f32::consts::PI / 2.0),
+ UiTransform {
+ rotation: Rot2::degrees(90.),
  ..default()
  },
  ));