Expose DAST artifact directory

What does this MR do and why?

Describe in detail what your merge request does and why.

This Merge Request exposes all files on the dast_artifacts directory.

DAST should write all of its artifacts to an artifacts directory dast_artifacts/, and all the files in that directory should be exposed by default for customers to download as described on #356489 (closed).

Screenshots or screen recordings

These are strongly recommended to assist reviewers and reduce the time to merge your change.

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.