Merge pull request buildkite-plugins#249 from buildkite-plugins/renovate/ruby-3.4-alpine

Update ruby:3.4-alpine Docker digest to cb6a5cb

Author: james2791

docker-compose.yml

@@ -1,7 +1,7 @@
 version: '2'
 services:
   ruby:
-    image: ruby:3.4-alpine@sha256:e97433bb401592615f94bffc5c0dadbf0b161619ebac5a0af044cd7b673a6f12
+    image: ruby:3.4-alpine@sha256:cb6a5cb7303314946b75fa64c96d8116f838b8495ffa161610bd6aaaf9a70121
     command: rake
     working_dir: /src
     volumes: