fix gemnasium-maven also creating gemnasium job

~"Category:Dependency Scanning" ~bug devopssecure Community contribution

What does this MR do?

Currently if DS_DEFAULT_ANALYZERS is set to gemnasium-maven or gemnasium-python it may also create an additional job as if it was set to gemnasium if all other conditions (project containing certain languages) are met.

This MR fixes this behavior for cases like gemnasium-* but retains the ability to define multiple analyzers like gemnasium,gemnasium-maven.

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WIP:

• add changelog entry (What would be a good title?)
• thoughts about a regression test?

Does this MR meet the acceptance criteria?

Conformity

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

Availability and Testing

Adding a regression test might be an option, but seems complicated to me for these regex checks within variables.

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers

Closes #39951 (closed)