[roll] Roll fuchsia [rust][wlancfg] unused muts, shush false positives

New toolchain does a clippy check for unused mutable references when a
normal reference would do fine.

Fix the instances when that is actually the case.

Unfortunately it also has false positives with async fns, silence the
clippy otherwise.

Original-Bug: 130265
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/891840
Original-Revision: 9254e521d24d9850321e5e8a60b8fab8fe0a58d1
GitOrigin-RevId: 116c1db8f616c9205ad7f71d7812a8945ec5b9d3
Change-Id: Icda9d8341e4e9a30f4085069fff384bb23d4e8c7
diff --git a/stem b/stem
index 4bddf9f..863ff0c 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="f2dd67e5093e3d0ebbb0631aab9e74cd74e8401c"/>
+             revision="9254e521d24d9850321e5e8a60b8fab8fe0a58d1"/>
   </projects>
   <hooks>
     <hook name="install-environment"