modules/mavlink: update for sha256sum improvements

tpwrules · peterbarker · commit ca35793c389b · 2026-03-01T16:59:06.000+11:00
Includes pymavlink generator code improvements to save ~400 bytes of
stack on Cortex M when signing.
diff --git a/modules/mavlink b/modules/mavlink
@@ -1 +1 @@
-Subproject commit 950458b454d3fc2571e11497fe1f12310c14af1d
+Subproject commit 5ac5ff84e66ca50d74ba0c1bb7caffb3dfd412f0
