ci: add freeze/** branches to CI trigger

freeze/rc branches were not covered by the push trigger, leaving
RC-stage work untested. Adds 'freeze/**' alongside existing patterns.

.forgejo/workflows/ci.yml

@@ -7,7 +7,7 @@ name: CI
 
 on:
   push:
-    branches: [main, 'feature/**', 'fix/**']
+    branches: [main, 'feature/**', 'fix/**', 'freeze/**']
   pull_request:
     branches: [main]