manifest: Update sdk-zephyr to have GRTC and timer tests for nRF54L20

Run GRTC tests for nRF54L20 target.

Signed-off-by: Adam Kondraciuk <[email protected]>

Author: adamkondraciuk

west.yml

@@ -72,7 +72,7 @@ manifest:
     # https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/guides/modules.html
     - name: zephyr
       repo-path: sdk-zephyr
-      revision: 8ceab93c866d584201621703dee15a77107e7363
+      revision: pull/1919/head
       import:
         # In addition to the zephyr repository itself, NCS also
         # imports the contents of zephyr/west.yml at the above