Updates the Stan submodule to 4d65d4404.

stan-buildbot · stan-buildbot · commit da7fe82f3446 · 2025-12-12T04:34:45.000-05:00
diff --git a/StanHeaders/inst/include/upstream b/StanHeaders/inst/include/upstream
@@ -1 +1 @@
-Subproject commit ec3f1ea6dc40d5ee42dd53d15afbdcfe31352b9b
+Subproject commit 4d65d4404fd460a2cfad3107990028567140002b
