Update CTS ref for merged test updates.

MarkCallow · MarkCallow · commit b9218bc503dd · 2025-04-16T16:36:38.000+09:00
diff --git a/tests/cts b/tests/cts
@@ -1 +1 @@
-Subproject commit 7801a67d4a42138c8bc056ef78df49f295c4b023
+Subproject commit 637c9c69768bfcc1015f9609c9685fb2a17a41c4
