Fix github actions

Author: alexandermeindl

.github/workflows/tests.yml

@@ -14,6 +14,8 @@ jobs:
         redmine: ['6.0-stable', '6.1-stable', 'master']
         db: ['postgres', 'mysql']
         exclude:
+          - ruby: '3.1'
+            redmine: 6.1-stable
           - ruby: '3.1'
             redmine: master
           - ruby: '3.4'