Allow ci_separated_caches to be updated from API

!86876 (merged) added option to enable/disable separated caches between protected and not protected branches. ci_separated_caches attribute is exposed to API, but it cannot be updated from Update Project API.

ci_separated_caches should be able to update from Update project API.

Possible Fix:

• Add ci_separated_caches to update_params_at_least_one_of