[roll] Roll fuchsia [build][rust] Improve default toolchain detection

Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/861396
Original-Revision: 99fd8a081ee69bbd97b550ed3d453cc35d7526ff
GitOrigin-RevId: 3a60a7aa4421c1f9744a7d58a91c5ccd639647a8
Change-Id: I3aba0776b70672531af860a5003a15efbb3bb762
diff --git a/stem b/stem
index 4180a0c..f9e747b 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="349c69dafddfdff65e83981c7f2b89870733996d"/>
+             revision="99fd8a081ee69bbd97b550ed3d453cc35d7526ff"/>
   </projects>
   <hooks>
     <hook name="install-environment"