ci: update CI workflow to copy node_modules instead of bun

.gitea/workflows/ci.yml

@@ -84,12 +84,10 @@ jobs:
       - run: cd /home/bun/app && ls -la
       - name: Checkout Code
         uses: actions/checkout@v4
-      - name: Install bun
-        uses: oven-sh/setup-bun@v2
       - name: Install dependencies
         run: |
           cd frontend
-          bun install
+          cp -r /home/bun/app/node_modules .
       - name: Test build
         run: |
           cd frontend