Missing config schema for restrict_ip.settings:ip_whitelist

Problem/Motivation

RestrictIpService::buildWhitelistedIpAddresses() reads $this->config->get('ip_whitelist') and the README documents $config['restrict_ip.settings']['ip_whitelist'] = [...] as the intended way to provide whitelisted IPs. The key is not declared in config/schema/restrict_ip.schema.yml, which combined with FullyValidatable: ~ causes Config Inspector to flag restrict_ip.settings:ip_whitelist as missing schema.

Steps to reproduce

Proposed resolution

Declare ip_whitelist as a nullable sequence of strings (see attached patch).

Remaining tasks

User interface changes

API changes

Data model changes