fix: revert GridIntoIterator to pop() since ordering is not guaranteed; fix fmt

Co-authored-by: samueltardieu <44656+samueltardieu@users.noreply.github.com>

Author: Copilot

src/grid.rs

@@ -579,13 +579,7 @@ impl Iterator for GridIntoIterator {
                 }
             }
         } else {
-            self.grid
-                .exclusions
-                .get_index(self.x)
-                .inspect(|_| {
-                    self.x += 1;
-                })
-                .copied()
+            self.grid.exclusions.pop()
         }
     }
 }

tests/grid.rs

@@ -641,15 +641,7 @@ fn iter_dense_grid_yields_exact_vertices() {
     g.fill();
     g.remove_vertex((1, 0));
     g.remove_vertex((0, 2));
-    let mut expected = vec![
-        (0, 0),
-        (2, 0),
-        (0, 1),
-        (1, 1),
-        (2, 1),
-        (1, 2),
-        (2, 2),
-    ];
+    let mut expected = vec![(0, 0), (2, 0), (0, 1), (1, 1), (2, 1), (1, 2), (2, 2)];
     expected.sort_unstable();
     let mut via_iter = g.iter().collect::<Vec<_>>();
     via_iter.sort_unstable();