ci: update Deckard in attempt to make CI more reliable

Changes related to monotonic fake time and detection logic for overload
should make CI a little bit more reliable. It should be even better once
we combine overload-detection with some kind of auto-retry.

diff --git a/tests/deckard b/tests/deckard
index 33d826de7ea143c7eff28c9c0ce0c3ad6e0f6ae1..5436af53cb393ce38519c87868e303d9993fd5dd 160000 (submodule)
--- a/tests/deckard
+++ b/tests/deckard
@@ -1 +1 @@
-Subproject commit 33d826de7ea143c7eff28c9c0ce0c3ad6e0f6ae1
+Subproject commit 5436af53cb393ce38519c87868e303d9993fd5dd