BUG: VCs are still accessible and responding after the space VC flag is disabled

[Comoque1]

Describe the bug A clear and concise description of what the bug is.

To Reproduce Steps to reproduce the behavior:

1. Go to https://acc-alkem.io/vcs3/dashboard or create a new space
2. Enable 'Interact with virtual contributors' for the space
3. Add VCs to the community
4. Mention a VC - response is returned
5. Disable 'Interact with virtual contributors' for the space
6. Mention a VC - response is returned

Expected behavior Responses are not returned after 'Interact with virtual contributors' for the space is disabled.