Fix Shader for SkeletonGizmo to follow renderer's reversed-z change

Co-authored-by: Lyuma <[email protected]>

editor/plugins/skeleton_3d_editor_plugin.cpp

@@ -922,7 +922,7 @@ void vertex() {
 
 	VERTEX = VERTEX;
 	POSITION = PROJECTION_MATRIX * VIEW_MATRIX * MODEL_MATRIX * vec4(VERTEX.xyz, 1.0);
-	POSITION.z = mix(POSITION.z, 0.0, 0.999);
+	POSITION.z = mix(POSITION.z, POSITION.w, 0.999);
 	POINT_SIZE = point_size;
 }
 
@@ -1201,7 +1201,7 @@ void vertex() {
 	}
 	VERTEX = VERTEX;
 	POSITION = PROJECTION_MATRIX * VIEW_MATRIX * MODEL_MATRIX * vec4(VERTEX.xyz, 1.0);
-	POSITION.z = mix(POSITION.z, 0, 0.998);
+	POSITION.z = mix(POSITION.z, POSITION.w, 0.998);
 }
 void fragment() {
 	ALBEDO = COLOR.rgb;