Add PartialEq to Anchor (bevyengine#10424)

Add PartialEq to Anchor.

# Objective

Make Anchor work with bevy_egui's ComboBox.

## Solution

Make Anchor PartialEq.

crates/bevy_sprite/src/sprite.rs

@@ -25,7 +25,7 @@ pub struct Sprite {
 
 /// How a sprite is positioned relative to its [`Transform`](bevy_transform::components::Transform).
 /// It defaults to `Anchor::Center`.
-#[derive(Component, Debug, Clone, Copy, Default, Reflect)]
+#[derive(Component, Debug, Clone, Copy, PartialEq, Default, Reflect)]
 #[doc(alias = "pivot")]
 pub enum Anchor {
     #[default]