Test ruby 3.4 (#273)

Author: ntkme

.github/workflows/build.yml

@@ -48,6 +48,7 @@ jobs:
           - '3.1'
           - '3.2'
           - '3.3'
+          - '3.4'
           - jruby
           - truffleruby
           - truffleruby+graalvm
@@ -66,6 +67,9 @@ jobs:
           - os: ubuntu-latest
             container:
               image: docker.io/library/ruby:3.3-alpine
+          - os: ubuntu-latest
+            container:
+              image: docker.io/library/ruby:3.4-alpine
           - os: ubuntu-latest
             container:
               image: docker.io/nixos/nix:latest