ci: run Gitea tests one package at a time

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.gitea/workflows/ci.yaml

@@ -32,4 +32,5 @@ jobs:
         run: go vet ./...
       - name: test
         continue-on-error: true
-        run: go test -timeout 5m ./...
+        # -p 1: one package at a time, lower peak disk/memory on small CI pods
+        run: go test -p 1 -timeout 5m ./...