chore: Bump Rust edition to 2024 (#27800)

Follow-up to https://github.com/zed-industries/zed/pull/27791

Release Notes:

- N/A

crates/sum_tree/src/sum_tree.rs

@@ -134,7 +134,7 @@ where
     D3: Dimension<'a, S>,
 {
     fn cmp(&self, cursor_location: &((D1, D2), D3), cx: &S::Context) -> Ordering {
-        self.cmp(&cursor_location.0 .0, cx)
+        self.cmp(&cursor_location.0.0, cx)
     }
 }
 
@@ -1418,11 +1418,7 @@ mod tests {
         let mut ix = 0;
         let iterator = std::iter::from_fn(|| {
             ix = (ix + 1) % 2;
-            if ix == 1 {
-                Some(1)
-            } else {
-                None
-            }
+            if ix == 1 { Some(1) } else { None }
         });
         assert_eq!(SumTree::from_iter(iterator, &()).items(&()), vec![1]);
     }