Remove things that have been deprecated for over a year (#7099)

Removes all things that were marked `#[deprecated]` more than 12 months
ago

crates/egui_extras/src/lib.rs

@@ -25,9 +25,6 @@ mod table;
 #[cfg(feature = "chrono")]
 pub use crate::datepicker::DatePickerButton;
 
-#[doc(hidden)]
-#[expect(deprecated)]
-pub use crate::image::RetainedImage;
 pub(crate) use crate::layout::StripLayout;
 pub use crate::sizing::Size;
 pub use crate::strip::*;