Rust 1.85 (#25272)

Closes #ISSUE

Release Notes:

- N/A *or* Added/Fixed/Improved ...

---------

Co-authored-by: Anthony Eid <hello@anthonyeid.me>

crates/gpui/src/text_system.rs

@@ -670,6 +670,15 @@ pub struct TextRun {
     pub strikethrough: Option<StrikethroughStyle>,
 }
 
+#[cfg(all(target_os = "macos", test))]
+impl TextRun {
+    fn with_len(&self, len: usize) -> Self {
+        let mut this = self.clone();
+        this.len = len;
+        this
+    }
+}
+
 /// An identifier for a specific glyph, as returned by [`TextSystem::layout_line`].
 #[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
 #[repr(C)]