[nrf fromtree] west.yml: MCUboot synchronization from upstream

Update Zephyr fork of MCUboot to revision:
  96576b341ee19f1c3af6622256b0d4f3d408e1e3

Brings following Zephyr relevant fixes:

  - 96576b34 boot: zephyr: socs: stm32h7s7xx: Add support for
    ext_flash_app variant
  - 56538cf6 bootutil: Move update-independent code
  - fccd8905 loader: Move boot_get_max_app_size(..) API
  - 0248a023 bootutil: Move state-independent area APIs
  - f2d3f00a loader: Unify image check API.
  - dcc66e51 loader: Unify header_valid(..) API
  - 257265c8 loader: Optimize boot_check_header_erased(..)
  - 76e56e4f loader: Rename boot_version_cmp
  - 5311589b loader: Fix compile-time issues in loader.c
  - 606a1934 boot: zephyr: socs: add overlay & conf for
    stm32h573xx_ext_flash_app
  - 521fc0bf bootutil: Conditionally include mbedtls/ oid.h,
    asn1.h
  - 71b41e38 boot: zephyr: boards: remove nrf54h20dk overlay
  - 2fc1bd84 bootutil: Drop slot number and boot_state from most
    boot_enc functions
  - 1dd8ae60 boot: zephyr: rework stm32h750b_dk board overlay &
    conf

Signed-off-by: Jamie McCrae <[email protected]>
(cherry picked from commit cd2079f)

Author: nordicjm

west.yml

@@ -316,7 +316,7 @@ manifest:
       groups:
         - crypto
     - name: mcuboot
-      revision: b192716c969ad358bb3a1db60c898212f3275c55
+      revision: 96576b341ee19f1c3af6622256b0d4f3d408e1e3
       path: bootloader/mcuboot
       groups:
         - bootloader