Update rubocop-performance requirement from ~> 1.25.0 to ~> 1.26.0 (#610)

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

Author: dependabot[bot]

Gemfile

@@ -19,7 +19,7 @@ group :test do
   gem "oj", "~> 3.14" if ENV["WITH_OJ_GEM"] == "true"
   gem "rspec", "~> 3.13.0"
   gem "rubocop", "~> 1.78.0"
-  gem "rubocop-performance", "~> 1.25.0"
+  gem "rubocop-performance", "~> 1.26.0"
   gem "simplecov", "~> 0.22.0"
   gem "simplecov-console", "~> 0.9.1"
 end