Update rubocop-performance requirement from 1.19.1 to 1.20.1

Updates the requirements on [rubocop-performance](https://github.com/rubocop/rubocop-performance) to permit the latest version.
- [Release notes](https://github.com/rubocop/rubocop-performance/releases)
- [Changelog](https://github.com/rubocop/rubocop-performance/blob/master/CHANGELOG.md)
- [Commits](rubocop/rubocop-performance@v1.19.1...v1.20.1)

---
updated-dependencies:
- dependency-name: rubocop-performance
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile

@@ -7,5 +7,5 @@ gem "rake", "~> 13.0"
 gem "rubocop", "1.58.0"
 gem "rubocop-minitest", "0.33.0"
 gem "rubocop-packaging", "0.5.2"
-gem "rubocop-performance", "1.19.1"
+gem "rubocop-performance", "1.20.1"
 gem "rubocop-rake", "0.6.0"