Updates the Stan submodule to 8bef2916f.

stan-buildbot · stan-buildbot · commit 12140bdd94b5 · 2026-01-06T11:17:14.000-05:00
diff --git a/stan b/stan
@@ -1 +1 @@
-Subproject commit 854756b201a831a7b2cf0bb12ad77b08adb868a4
+Subproject commit 8bef2916f30cfdcbfa30fcced12e00bdbdf895ae
