manifest: update sdk-zephyr

Include:
soc: nordic: nrf54h: Implement idle with cache retained state
sdk-zepjyr PR #: 3249
zephyr upstream PR #: 95474

Signed-off-by: Sebastian Głąb <[email protected]>

Author: nordic-segl

west.yml

@@ -65,7 +65,7 @@ manifest:
     # https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/guides/modules.html
     - name: zephyr
       repo-path: sdk-zephyr
-      revision: c539d475b659949cf96c1638cf7fbafbf64d33f3
+      revision: pull/3249/head
       import:
         # In addition to the zephyr repository itself, NCS also
         # imports the contents of zephyr/west.yml at the above