Update SAST template to execute GitLab Advanced SAST by default

What does this MR do and why?

Updates the following SAST templates to execute GitLab Advanced SAST by default:

• SAST.gitlab-ci.yml
• SAST.latest.gitlab-ci.yml

References

Update SAST template to execute GitLab Advanced... (#514659) • Unassigned • 19.0

Tests

Case	Variables	gitlab-advanced-sast executed?	semgrep executed?
File ext supported by both GLAS and semgrep	None	✅	❌
	GITLAB_ADVANCED_SAST_ENABLED: true	✅	❌
	GITLAB_ADVANCED_SAST_ENABLED: false	❌	✅
File ext supported by both GLAS and semgrep, and another ext supported by only semgrep	None	✅	✅
	GITLAB_ADVANCED_SAST_ENABLED: true	✅	✅
	GITLAB_ADVANCED_SAST_ENABLED: false	❌	✅
File ext supported by only GLAS	None	✅	❌
	GITLAB_ADVANCED_SAST_ENABLED: true	✅	❌
	GITLAB_ADVANCED_SAST_ENABLED: false	❌	❌
File ext supported by only semgrep	None	❌	✅
	GITLAB_ADVANCED_SAST_ENABLED: true	❌	✅
	GITLAB_ADVANCED_SAST_ENABLED: false	❌	✅
File ext not supported by semgrep or GLAS	Not applicable	❌	❌