Update rubocop-performance requirement from 1.25.0 to 1.26.0 (#68)

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@v1.25.0...v1.26.0)

---
updated-dependencies:
- dependency-name: rubocop-performance
  dependency-version: 1.26.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Gemfile

@@ -5,5 +5,5 @@ gem "rake", "~> 13.0"
 gem "rubocop", "1.80.2"
 gem "rubocop-minitest", "0.38.2"
 gem "rubocop-packaging", "0.6.0"
-gem "rubocop-performance", "1.25.0"
+gem "rubocop-performance", "1.26.0"
 gem "rubocop-rake", "0.7.1"