Fix renovate error

Signed-off-by: Nick Slowinski <nick@nick-slowinski.de>

.forgejo/workflows/build.yaml

@@ -1,9 +1,8 @@
 name: Build website
 on:
   push:
-    branches:
-      - !'main'
-      - '*'
+    branches-ignore:
+      - main
   pull_request:
     types: [opened, synchronize, reopened]