Use latest released ruby version for gh workflows

Author: stefannibrasil

.github/workflows/bench.yml

@@ -18,7 +18,7 @@ jobs:
     - uses: actions/checkout@v6
     - uses: ruby/setup-ruby@v1
       with:
-        ruby-version: '3.4'
+        ruby-version: '4.0'
     - name: Install dependencies
       run: bundle install
 

.github/workflows/ruby.yml

@@ -25,7 +25,7 @@ jobs:
       - uses: actions/checkout@v6
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: '3.4'
+          ruby-version: '4.0'
 
       - name: Install dependencies
         run: bundle install