message: Reinstate export of isRuleGroup and remove deprecation notice
diff: import type { RuleGroupType, RuleGroupTypeAny, RuleGroupTypeIC, RuleType } from '../types';
  -const isRuleGroup = (rg: RuleType | RuleGroupTypeAny): rg is RuleGroupTypeAny =>
  +/**
  + * Determines if this is either a RuleGroupType or RuleGroupTypeIC.
  + * `'rules' in query` can be used as an alternative.
  + */
  +export const isRuleGroup = (rg: RuleType | RuleGroupTypeAny): rg is RuleGroupTypeAny =>
  typeof rg === 'object' && 'rules' in rg && Array.isArray(rg.rules);
  export const isRuleGroupType = (rg: RuleType | RuleGroupTypeAny): rg is RuleGroupType =>
  