Restrict disallowed document types from being uploaded

Summary

Users are currently able to upload all types of documents, including videos, despite a message indicating that video uploads are not allowed. The system should enforce restrictions on disallowed file types.

Steps to Reproduce

1. Attempt to upload a video file to the platform.
2. Observe that the upload succeeds without any restriction.

Expected Behaviour

Uploading video files should be blocked or rejected, as indicated by the message that video uploads are not allowed.

Actual Behaviour

Video files are accepted and uploaded successfully, contradicting the restriction message.

Environment

Not provided.

Reported by retoor via DevPlace.