Merge branch 'docs/dependency-scanning-pip' into 'master'

Mention limitation of requirements.txt in Dependency scanning docs

Closes gitlab-ce#52824

See merge request gitlab-org/gitlab-ee!8439

doc/user/project/merge_requests/dependency_scanning.md

 # Dependency Scanning **[ULTIMATE]**
 
 > [Introduced](https://gitlab.com/gitlab-org/gitlab-ee/issues/5105)
-in [GitLab Ultimate][ee] 10.7.
+in [GitLab Ultimate](https://about.gitlab.com/pricing/) 10.7.
 
 ## Overview
 
@@ -29,7 +29,7 @@ The following languages and dependency managers are supported.
 | Language (package managers)                                                 | Scan tool                                                                                                                         |
 |-----------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------|
 | JavaScript ([npm](https://www.npmjs.com/), [yarn](https://yarnpkg.com/en/)) | [gemnasium](https://gitlab.com/gitlab-org/security-products/gemnasium/general), [Retire.js](https://retirejs.github.io/retire.js)         |
-| Python ([pip](https://pip.pypa.io/en/stable/))                              | [gemnasium](https://gitlab.com/gitlab-org/security-products/gemnasium/general)                                                            |
+| Python ([pip](https://pip.pypa.io/en/stable/)) (only `requirements.txt` supported)  | [gemnasium](https://gitlab.com/gitlab-org/security-products/gemnasium/general)                                                            |
 | Ruby ([gem](https://rubygems.org/))                                         | [gemnasium](https://gitlab.com/gitlab-org/security-products/gemnasium/general), [bundler-audit](https://github.com/rubysec/bundler-audit) |
 | Java ([Maven](https://maven.apache.org/))                                   | [gemnasium](https://gitlab.com/gitlab-org/security-products/gemnasium/general)                                                            |
 | PHP ([Composer](https://getcomposer.org/))                                  | [gemnasium](https://gitlab.com/gitlab-org/security-products/gemnasium/general)                                                            |