feat: mode=silent (#28396)

docs/usage/configuration-options.md

lib/config/options/index.ts

lib/workers/repository/config-migration/index.spec.ts

lib/workers/repository/config-migration/index.ts

lib/workers/repository/dependency-dashboard.spec.ts

lib/workers/repository/dependency-dashboard.ts

lib/workers/repository/error-config.spec.ts

lib/workers/repository/error-config.ts

lib/workers/repository/init/index.spec.ts

lib/workers/repository/init/index.ts

lib/workers/repository/init/merge.spec.ts

lib/workers/repository/init/merge.ts

lib/workers/repository/onboarding/branch/check.spec.ts

lib/workers/repository/onboarding/branch/check.ts

lib/workers/repository/onboarding/branch/create.ts

lib/workers/repository/process/deprecated.spec.ts

lib/workers/repository/process/deprecated.ts

lib/workers/repository/update/branch/index.spec.ts

lib/workers/repository/update/branch/index.ts