[roll] Roll fuchsia [ffx][fho] Change verify_schema to associated func.

In VerifiedMachineWriter there is a function that takes `&self` that is
unused. As shown in this CL, requiring this makes it difficult to test
things when a writer is passed by value into a function.

This changes the verify_schema function to be an associated function
instead of a method to rectify this.

Original-Bug: b/339725104
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1046093
Original-Revision: 0514351ab8e6d2b82828bc0b1cc3e5751c5f0154
GitOrigin-RevId: 181b536f73395111ffd00b8df92ee4ed8597ea90
Change-Id: I44823b7e64f63699f86475c48799d2b52eaad8fd
diff --git a/stem b/stem
index 30c0c0a..cbe51c9 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="ca24101f6ab97b5387b26ff0cb04683bb9d6ecf6"/>
+             revision="0514351ab8e6d2b82828bc0b1cc3e5751c5f0154"/>
   </projects>
   <hooks>
     <hook name="install-environment"