fixup! feat(core): Implement GetFirmwareHash message.

core/embed/extmod/modtrezorutils/modtrezorutils.c

@@ -119,7 +119,7 @@ STATIC mp_obj_t mod_trezorutils_halt(size_t n_args, const mp_obj_t *args) {
 STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_trezorutils_halt_obj, 0, 1,
                                            mod_trezorutils_halt);
 
-/// def firmware_hash(challenge: bytes | None) -> bytes:
+/// def firmware_hash(challenge: bytes | None = None) -> bytes:
 ///     """
 ///     Computes the Blake2s hash of the firmware with an optional challenge as
 ///     the key.

core/mocks/generated/trezorutils.pyi

@@ -43,7 +43,7 @@ def halt(msg: str | None = None) -> None:
 
 
 # extmod/modtrezorutils/modtrezorutils.c
-def firmware_hash(challenge: bytes | None) -> bytes:
+def firmware_hash(challenge: bytes | None = None) -> bytes:
     """
     Computes the Blake2s hash of the firmware with an optional challenge as
     the key.