Unpublished Products are listed and creating a subscription for those leads to a silent error

## Bug description

Unpublished Product as listed in Product catalog and when a user tries to create a subscription for those the process silently fails with the following error in the network console:

```json
{"code":"BadRequest","message":"{\"error\":{\"code\":\"ValidationError\",\"message\":\"Operation is not allowed in the current product state\",\"details\":null}}"}
```

## Reproduction steps

1. Create an unpublished Product on API management that requires subscription, **unpublished** and developer group has access granted.
2. Confirm it is visible on the developer portal for a logged in user.
3. Try to subscribe to the Product.

## Expected behavior

Unpublished Products are not listed.

## Is self-hosted portal?

Yes

(Also managed devportal)

## Release tag or commit SHA (if using self-hosted version)

2.32.0

## API Management service name

N/A

## Environment

- Operating system: [e.g., iOS]: N/A
- Browser: [e.g., Google Chrome, Safari]: N/A
- Version: NA/

## Additional context

Add any other context about the problem here, including screenshots.

Start by reproducing the issue in the developer portal using an unpublished Product that requires a subscription, then trace the Product catalog listing and subscription flow. Done means unpublished Products are not listed for eligible users and attempting a subscription no longer fails silently.

Written by the indexing model from the issue text.