Derive Copy and Clone for FontAtlasKey (#21315)

# Objective

For convenience, need to collect some.

Author: ickshonpe

crates/bevy_text/src/font_atlas_set.rs

@@ -49,7 +49,7 @@ pub fn remove_dropped_font_atlas_sets(
 /// Identifies a font size and smoothing method in a [`FontAtlasSet`].
 ///
 /// Allows an `f32` font size to be used as a key in a `HashMap`, by its binary representation.
-#[derive(Debug, Hash, PartialEq, Eq)]
+#[derive(Debug, Hash, PartialEq, Eq, Copy, Clone)]
 pub struct FontAtlasKey(pub u32, pub FontSmoothing);
 
 /// A map of font sizes to their corresponding [`FontAtlas`]es, for a given font face.