Downgrade s2n-tls to v1.5.15

lauzadis · lauzadis · commit b6520da588c7 · 2025-04-15T12:42:21.000-04:00
diff --git a/crt/s2n b/crt/s2n
@@ -1 +1 @@
-Subproject commit ca136ce414216e687212672ca8c7e6dbf4bd04c1
+Subproject commit bb9c5991877c6a749981204131e6e47845adbe3d
