chore(tests): add test run for maint-*

Author: utnapischtim

.github/workflows/tests.yml

@@ -2,7 +2,7 @@
 #
 # This file is part of Invenio.
 # Copyright (C) 2016-2024 CERN.
-# Copyright (C) 2022-2024 Graz University of Technology.
+# Copyright (C) 2022-2026 Graz University of Technology.
 # Copyright (C) 2024 KTH Royal Institute of Technology.
 #
 # Invenio is free software; you can redistribute it and/or modify
@@ -15,9 +15,11 @@ on:
     branches:
       - master
       - "feature/*"
+      - "maint-**"
   pull_request:
     branches:
       - master
+      - "maint-**"
       - "feature/*"
   schedule:
     # * is a special character in YAML so you have to quote this string