Expand selections to Replace block boundaries (#20092)

Release Notes:

- N/A

---------

Co-authored-by: Antonio Scandurra <me@as-cii.com>
Co-authored-by: Max Brunsfeld <maxbrunsfeld@gmail.com>
Co-authored-by: Antonio <antonio@zed.dev>
Co-authored-by: Max <max@zed.dev>

crates/diagnostics/src/diagnostics_tests.rs

@@ -986,6 +986,7 @@ fn editor_blocks(
                                     em_width: px(0.),
                                     max_width: px(0.),
                                     block_id,
+                                    selected: false,
                                     editor_style: &editor::EditorStyle::default(),
                                 });
                                 let element = element.downcast_mut::<Stateful<Div>>().unwrap();