fix: Install kustomize directly from GitHub instead of using external action

Replace imranismail/setup-kustomize action with direct kustomize installation from kubernetes-sigs GitHub repository. This avoids authentication issues with Gitea.

🤖 Generated with Claude Code

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

.gitea/workflows/build-deploy.yml

@@ -75,7 +75,10 @@ jobs:
             -n sqdc-dashboard \
             --dry-run=client -o yaml | kubectl apply -f -
 
-      - uses: imranismail/setup-kustomize@v2
+      - name: Install Kustomize
+        run: |
+          curl -s "https://raw.githubusercontent.com/kubernetes-sigs/kustomize/master/hack/install_kustomize.sh" | bash
+          sudo mv kustomize /usr/local/bin/
 
       - name: Deploy with Kustomize
         run: |