Update submodule to v0.96.4.0. (#15164)

Co-authored-by: moonheart08 <moonheart08@users.noreply.github.com>

diff --git a/RobustToolbox b/RobustToolbox
index dae4761b72f376d0545d81600e56273ff6fb5c91..b31876ff03d0407039197767eaf8b55d2b215481 160000 (submodule)
--- a/RobustToolbox
+++ b/RobustToolbox
@@ -1 +1 @@
-Subproject commit dae4761b72f376d0545d81600e56273ff6fb5c91
+Subproject commit b31876ff03d0407039197767eaf8b55d2b215481