[roll] Roll fuchsia [build][sdk] Fix mypy issues in generate_repository.py

Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1252734
Original-Revision: f637bcfd42ccebc3c453e515bed97b9b362e53ce
GitOrigin-RevId: 36ebc91ff7001d1a3e8957f69290a321064532cc
Change-Id: I6257f6babfb333f7f96494d2b11d9089b1ec3361

stem

diff --git a/stem b/stem
index 824c455..f91399d 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="fe5a1e61bf78bb943abb68a8f34a952212305969"
+             revision="f637bcfd42ccebc3c453e515bed97b9b362e53ce"
              />
   </projects>
   <hooks>