Updates the Stan submodule to 06d7216fb.

stan-buildbot · stan-buildbot · commit 9d610e97e70c · 2026-02-11T17:33:30.000-05:00
diff --git a/StanHeaders/inst/include/upstream b/StanHeaders/inst/include/upstream
@@ -1 +1 @@
-Subproject commit db9851c7969e9d363100b20e826acbd4521329e8
+Subproject commit 06d7216fb391542a320343d1af61e365c9227d28
