Back off of trilerp w/ skia bug

Skia's CPU backend has some bug related to trilerp (shown by some of our mesh examples). This make the cloud renderer produce bad results.

This PR backs off the sampling to still use mipmaps, but to just bilerp the chosen level, and not tri-lerp it. Very slight degrade in quality, but still much better than just bilerp.

Diffs=
dc76fda7d Back off of trilerp w/ skia bug
diff --git a/.rive_head b/.rive_head
index c218643..508d525 100644
--- a/.rive_head
+++ b/.rive_head
@@ -1 +1 @@
-e2d64593f3e48beeb08f27aadb20d261227a8ccd
+dc76fda7d2436c453a2016212d656d17a90c1ad4
diff --git a/skia/renderer/src/skia_factory.cpp b/skia/renderer/src/skia_factory.cpp
index 72cff4a..f948bf1 100644
--- a/skia/renderer/src/skia_factory.cpp
+++ b/skia/renderer/src/skia_factory.cpp
@@ -21,7 +21,8 @@
 
 using namespace rive;
 
-const SkSamplingOptions gSampling(SkFilterMode::kLinear, SkMipmapMode::kLinear);
+// skia's has/had bugs in trilerp, so backing down to nearest mip
+const SkSamplingOptions gSampling(SkFilterMode::kLinear, SkMipmapMode::kNearest);
 
 class SkiaRenderPath : public RenderPath {
 private: