bump pybind11 to latest

renefritze · renefritze · commit 5ab595ed259c · 2021-10-07T13:37:07.000+02:00
diff --git a/lib/pybind11 b/lib/pybind11
@@ -1 +1 @@
-Subproject commit 121360c6ae0fff0c97c64470508c11a0cc27bf94
+Subproject commit 97976c16fb7652f7faf02d76756666ef87adbe7d
