both frontend and backend are not starting simultaneously with make dev on windows

### Description of the bug:

both frontend and backend are not starting simultaneously. once i quit frontend then only backend starts

(myvenv) PS C:\Users\saiki\Documents\VSCode\gemini-fullstack-langgraph-quickstart> make dev
"Starting both frontend and backend development servers..."
make[1]: Entering directory 'C:/Users/saiki/Documents/VSCode/gemini-fullstack-langgraph-quickstart'
"Starting frontend development server..."

> frontend@0.0.0 dev
> vite

VITE v6.3.4 ready in 2717 ms

➜ Local: http://localhost:5173/app/
➜ Network: use --host to expose
➜ press h + enter to show help
q
make[1]: Leaving directory 'C:/Users/saiki/Documents/VSCode/gemini-fullstack-langgraph-quickstart'
make[1]: Entering directory 'C:/Users/saiki/Documents/VSCode/gemini-fullstack-langgraph-quickstart'
"Starting backend development server..."
INFO:langgraph_api.cli:

Welcome to

╦ ┌─┐┌┐┌┌─┐╔═╗┬─┐┌─┐┌─┐┬ ┬
║ ├─┤││││ ┬║ ╦├┬┘├─┤├─┘├─┤
╩═╝┴ ┴┘└┘└─┘╚═╝┴└─┴ ┴┴ ┴ ┴

- 🚀 API: http://127.0.0.1:2024
- 🎨 Studio UI: https://smith.langchain.com/studio/?baseUrl=http://127.0.0.1:2024
- 📚 API Docs: http://127.0.0.1:2024/docs

This in-memory server is designed for development and testing.
For production use, please use LangGraph Cloud.

### Actual vs expected behavior:

_No response_

### Any other information you'd like to share?

_No response_