Update test matrix

Exclude Rails versions that were EOL before the Ruby release dates.

Author: stympy

.github/workflows/ruby.yml

@@ -43,7 +43,14 @@ jobs:
             gemfile: rails8.gemfile
           - ruby: '3.1'
             gemfile: rails8.gemfile
-
+          - ruby: '3.4'
+            gemfile: rails6.1.gemfile
+          - ruby: 'ruby-head'
+            gemfile: rails6.1.gemfile
+          - ruby: '3.4'
+            gemfile: rails7.0.gemfile
+          - ruby: 'ruby-head'
+            gemfile: rails7.0.gemfile
     # Has to be top level to cache properly
     env:
       BUNDLE_GEMFILE: "gemfiles/${{ matrix.gemfile }}"