Add maintenance branch to CI push triggers

Author: mkrnr

.github/workflows/ci.yml

@@ -9,6 +9,7 @@ on:
   push:
     branches:
       - 'main'
+      - 'maintenance/*'
   pull_request:
     types:
         - opened

.github/workflows/ci/workflow_template.yml

@@ -4,6 +4,7 @@ on:
   push:
     branches:
       - 'main'
+      - 'maintenance/*'
   pull_request:
     types:
         - opened