manifest: Update sdk-zephyr

Includes an update to add a new MCUmgr OS group error code

Signed-off-by: Jamie McCrae <[email protected]>

Author: nordicjm

west.yml

@@ -69,7 +69,7 @@ manifest:
     # https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/guides/modules.html
     - name: zephyr
       repo-path: sdk-zephyr
-      revision: 76a46cb2baf310a06bbdb0b1d7d99394ec04a671
+      revision: 763e6a8ab82bd1a346a9b14a4b8fc7509c8441b6
       import:
         # In addition to the zephyr repository itself, NCS also
         # imports the contents of zephyr/west.yml at the above