west.yml: MCUboot synchronization from upstream

Update Zephyr fork of MCUboot to revision:
  f74b77cf7808919837c0ed14c2ead3918c546349

Brings following Zephyr relevant fixes:
  - f74b77cf imgtool: fix signing for fix-sig-pubkey public rsa
  - 439930ae boot_serial: Fix serial recovery for LPC55x and MCXNx

Signed-off-by: Jamie McCrae <jamie.mccrae@nordicsemi.no>