Add SECRET_DETECTION_EXCLUDED_PATHS to secrets scanner

Summary

Let's continue the SECRET_DETECTION_* convention for variables used in the secrets scanner by changing SAST_EXCLUDED_PATHS to SECRET_DETECTION_EXCLUDED_PATHS for the secrets scanner.

Improvements

Follows the convention set since the release of secrets v3.0

Involved components

• Updating the scanner
• Updating the docs
• Add SECRET_DETECTION_EXCLUDED_PATHS to the top level variables in the secret-detection template