Default for SAST_EXCLUDED_PATHS, DS_EXCLUDED_PATHS

What does this MR do?

Set default values for SAST_EXCLUDED_PATHS and DS_EXCLUDED_PATHS.

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

• SAST QA
• Dependency Scanning QA

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Closes #220014 (closed)