Remove extra line for supported langs

What does this MR do?

Removes the extra line in the dependency scanning documentation for supported languages.

See: gitaly!1764 (comment 274422494)

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• [-] Code review guidelines
• [-] Merge request performance guidelines
• [-] Style guides
• [-] Database guides
• [-] Separation of EE specific content