fix(actions): add bun install for bun runtime test

Author: ryoppippi

.github/workflows/ci.yml

@@ -96,6 +96,7 @@ jobs:
       - uses: oven-sh/setup-bun@v2
         with:
           bun-version: '1.1.39'
+      - run: bun install
       - run: bun run test:bun
       - uses: actions/upload-artifact@v4
         with: