apprt: Fix key callback input key assignments

Prior to this commit, two and three were not properly assigned. This
commit updates that to assign two to two, and three to three.

src/apprt/glfw.zig

@@ -821,8 +821,8 @@ pub const Surface = struct {
             .z => .z,
             .zero => .zero,
             .one => .one,
-            .two => .three,
-            .three => .four,
+            .two => .two,
+            .three => .three,
             .four => .four,
             .five => .five,
             .six => .six,