turbo configuration issue when creating a new back-end plugin

[Kashish Mittal]

Describe the bug

On creating a backend plugin with a dev/index.ts file present in it and running yarn start in the root directory, both the backend in packages/backend/index.ts and in the backend plugin's dev/index.ts run.
This issue does not appear with existing plugins as shown in the screenshot as they don't have a dev/index.ts file:

Expected Behavior

yarn start in the root directory runs without any errors

What are the steps to reproduce this bug?

1. run yarn new --select backend-plugin (named it hello)
2. run yarn --cwd packages/backend add @internal/backstage-plugin-hello-backend@^0.1.0
3. add backend.add(import('@internal/backstage-plugin-hello-backend')); to packages/backend/index.js
4. run yarn start

Versions of software used and environment

Built on top of commit 4cf349cd4bb17a1ec13b7d6d64c6f1492fbf028b of backstage-showcase

[Frank Kong]

For context, this causes port 7007 to be used by both, and typically caused the backstage-showcase backend to fail since the other plugin already grabbed port 7007.