Update dependency ruby to v4

Author: renovate[bot]

.github/workflows/lint.yml

@@ -26,7 +26,7 @@ jobs:
     - name: Setup ruby
       uses: ruby/setup-ruby@4fc31e1c823882afd7ef55985266a526c589de90 # v1.282.0
       with:
-        ruby-version: '3.4.8'
+        ruby-version: '4.0.1'
         bundler-cache: true
 
     - name: Lint swift-http-structured-headers.podspec