renovate/lib/config/migrations/custom/renovate-fork-migration.ts

import { isBoolean } from '@sindresorhus/is';
import { AbstractMigration } from '../base/abstract-migration.ts';

export class RenovateForkMigration extends AbstractMigration {
  override readonly deprecated = true;
  override readonly propertyName = 'renovateFork';

  override run(value: unknown): void {
    if (isBoolean(value)) {
      this.setSafely('forkProcessing', value ? 'enabled' : 'disabled');
    }
  }
}