fix(ci): Exclusion branche main du workflow CI

CI workflow now runs only on feature branches and PRs. On main, only CD workflow runs (which internally calls CI). This prevents duplicate CI runs.

.forgejo/workflows/ci.yml

@@ -2,7 +2,9 @@ name: CI - Validation
 
 on:
   push:
-    branches: ['**']  # All branches
+    branches:
+      - '**'
+      - '!main'  # Exclude main branch (CD workflow handles it)
   pull_request:
 
 jobs: