Revert recent anti-aliasing improvements (#24289)

This reverts commit 31fa414422.
This reverts commit b9e0aae49f.

`lyon` commit revert:

![image](https://github.com/user-attachments/assets/0243f61c-0713-416d-b8db-47372e04abaa)

`MSAA` commit revert:

![image](https://github.com/user-attachments/assets/b1a4a9fe-0192-47ef-be6f-52e03c025724)

cc @huacnlee , @\as-cii had decided to revert this PR due to a selection
right corner rendering bug.
Not sure what to propose for a fix from my side

Release Notes:

- N/A

crates/gpui/src/scene.rs

@@ -715,13 +715,6 @@ impl Path<Pixels> {
         }
     }
 
-    /// Move the start, current point to the given point.
-    pub fn move_to(&mut self, to: Point<Pixels>) {
-        self.contour_count += 1;
-        self.start = to;
-        self.current = to;
-    }
-
     /// Draw a straight line from the current point to the given point.
     pub fn line_to(&mut self, to: Point<Pixels>) {
         self.contour_count += 1;
@@ -751,8 +744,7 @@ impl Path<Pixels> {
         self.current = to;
     }
 
-    /// Push a triangle to the Path.
-    pub fn push_triangle(
+    fn push_triangle(
         &mut self,
         xy: (Point<Pixels>, Point<Pixels>, Point<Pixels>),
         st: (Point<f32>, Point<f32>, Point<f32>),