west: Point back to main after release

After releasing v4.2.0, move back to main.

Signed-off-by: Daniel DeGrasse <ddegrasse@tenstorrent.com>

Author: danieldegrasse

west.yml

@@ -12,7 +12,7 @@ manifest:
   projects:
     - name: zephyr
       remote: zephyrproject-rtos
-      revision: v4.2.0
+      revision: main
       import:
         # By using name-allowlist we can clone only the modules that are
         # strictly needed by the application.