Add missing include of SkPath (#45996)

This is needed as Skia refactors its #includes internally.

[C++, Objective-C, Java style guides]: https://github.com/flutter/engine/blob/main/CONTRIBUTING.md#style

Author: kjlubick

lib/web_ui/skwasm/contour_measure.cpp

@@ -6,6 +6,7 @@
 #include "helpers.h"
 
 #include "third_party/skia/include/core/SkContourMeasure.h"
+#include "third_party/skia/include/core/SkPath.h"
 
 using namespace Skwasm;