GH Actions: bump to Ruby 3.4 (was 3.2)

Author: generalmimon

.github/workflows/main.yml

@@ -14,7 +14,7 @@ jobs:
           submodules: true
       - uses: ruby/setup-ruby@v1
         with:
-          ruby-version: '3.2'
+          ruby-version: '3.4'
       - uses: actions/setup-python@v5
         with:
           python-version: '3.x'