[Enhancement]: Do all pre-build validations and show them upfront for deploys

### Affected Area

Dashboard/UI

### Problem Statement

When I tried to update a bench group that had an outdated node and Python dependency, it threw an error for one of them per deploy (as we throw an exception once we find a validation is false).

Maybe do all validations and send them as a batch to show them on the frontend?

Had to do 2 deploys to realise I had 2 different issues

### Proposed Solution

_No response_

Start by tracing the deploy pre-build validation flow in the Dashboard/UI area, focusing on where node and Python dependency checks are surfaced. Determine how multiple failed validations are currently stopped and reported. Done means a deploy reports all relevant validation failures together upfront instead of requiring separate deploys.

Written by the indexing model from the issue text.