Update rubocop-performance requirement from = 1.26.1 to = 1.27.0 - #53

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4, dependabot/fetch-metadata@v2. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/