Check SAST_DISABLE when SAST_DISABLE_DIND is set

What does this MR do?

Fix a bug where SAST is always running if SAST_DISABLE_DIND is set.

Conformity

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

closes #119345 (closed)