chore(deps): update dependency ruby to v3.4.8

Author: mailerlite-renovate[bot]

.github/workflows/main.yml

@@ -11,7 +11,7 @@ jobs:
     - name: Set up Ruby
       uses: ruby/setup-ruby@v1
       with:
-        ruby-version: 3.1
+        ruby-version: 3.4.8
 
     - name: Install Bundler
       run: gem install bundler -v 2.5.23

.github/workflows/publish_gem.yml

@@ -14,7 +14,7 @@ jobs:
       - name: Set up Ruby
         uses: ruby/setup-ruby@v1
         with:
-          ruby-version: 3.1
+          ruby-version: 3.4.8
 
       - name: Install Bundler
         run: gem install bundler -v 2.5.23