[roll] Roll fuchsia [rust-3p] Update num-traits to 0.2.19

Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1264405
Original-Revision: a0781d33abd8d6dcc85817e1aac782ecfa9216bb
GitOrigin-RevId: eab124261f8439c860a94269fe03c7260d041e26
Change-Id: Id69b534cae760a8833a56ecc01f948a02eac2eb1
diff --git a/stem b/stem
index 1d7ed75..f3e2aba 100644
--- a/stem
+++ b/stem
@@ -8,7 +8,7 @@
              root=""
              remote="https://fuchsia.googlesource.com/fuchsia"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="4ab7d9ca4ad09f540d2076a385a58f2f0a9ac8f9"
+             revision="a0781d33abd8d6dcc85817e1aac782ecfa9216bb"
              />
   </imports>
 </manifest>