Merge branch 'russell/remove-duplicate-dast-content' into 'master'

Remove duplicate DAST content

See merge request gitlab-org/gitlab!73027

doc/user/application_security/index.md

@@ -261,10 +261,6 @@ under your project's settings:
 </settings>
 ```
 
-## DAST On-Demand Scans
-
-If you don't want scans running in your normal DevOps process you can use on-demand scans instead. For more details, see [on-demand scans](dast/index.md#on-demand-scans). This feature is only available for DAST. If you run an on-demand scan against the default branch, it is reported as a "successful pipeline" and these results are included in the security dashboard and vulnerability report.
-
 ## Security report validation
 
 > - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/321918) in GitLab 13.11.