No ruby head

Author: smathy

.github/workflows/ruby.yml

@@ -23,7 +23,7 @@ jobs:
       fail-fast: false
       matrix:
         rails-version: [ '7.0', '7.1', '7.2', '8.0', head ]
-        ruby-version: ['3.1', '3.2', '3.3', '3.4', head]
+        ruby-version: ['3.1', '3.2', '3.3', '3.4']
         exclude:
           - rails-version: '8.0'
             ruby-version: '3.1'