Updates the Stan submodule to 3a880ada0.

stan-buildbot · stan-buildbot · commit 84fb5439bd0c · 2024-10-31T03:28:33.000-04:00
diff --git a/stan b/stan
@@ -1 +1 @@
-Subproject commit 9048555070493679287a25086e7b85b72ad9531f
+Subproject commit 3a880ada03f37b597026b8165bc9295179f6fb2a
