[roll] Roll fuchsia [rive-rs] Avoid non-local impl definitions

Rust recently added a new `non-local-definition` lint, that was tripped
by the nested implementation of `ObjectRef<'_, PathVertex>`. By pulling
the logic into a helper function, the linter no-longer fails.

Original-Bug: 327271893
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1041179
Original-Revision: de9a0f73e0341b11023550a933b924aeb8928e6a
GitOrigin-RevId: c4ec239535e73d7a428b5fe238a894a11d732290
Change-Id: I67aabc1e27b4d259667f6e0b6dab07de8bbfa8ae
diff --git a/stem b/stem
index 3e5b28c..66bd0cc 100644
--- a/stem
+++ b/stem
@@ -11,7 +11,7 @@
              githooks="integration/git-hooks"
              remote="https://fuchsia.googlesource.com/fuchsia"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="121cfa6e36c3112cde4b4f6398c830cd7d107b24"/>
+             revision="de9a0f73e0341b11023550a933b924aeb8928e6a"/>
   </projects>
   <hooks>
     <hook name="install-environment"