[roll] Roll fuchsia [build] Update comments referencing the old Zircon build.

Original-Bug: 60410

Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/474224
Original-Revision: 75455dfbc9679182a53e242819d9a3b4140a7bbf
GitOrigin-RevId: 8f7494b54bf7b85b0da45fb1dd41e7b210da4d8a
Change-Id: I6bfe0fe9111a12b286d396969d9895f766304e80
diff --git a/stem b/stem
index aa223e1..0011c80b 100644
--- a/stem
+++ b/stem
@@ -10,7 +10,7 @@
              githooks=""
              remote="https://fuchsia.googlesource.com/fuchsia"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="b5672f40032c889a71f50f24ce22646e09e4040b"/>
+             revision="75455dfbc9679182a53e242819d9a3b4140a7bbf"/>
   </projects>
   <hooks>
     <hook name="install-environment"