[Security Solution] Update CODEOWNERS for the Detection Engine team (#…

…164359)

## Summary

This PR updates the COEOWNERS file by adding missing Cypress tests
folders owned by the @elastic/security-detection-engine team.

.github/CODEOWNERS

@@ -1227,6 +1227,8 @@ x-pack/plugins/cloud_integrations/cloud_full_story/server/config.ts @elastic/kib
 /x-pack/plugins/security_solution/server/lib/sourcerer @elastic/security-detection-engine
 
 /x-pack/test/security_solution_cypress/cypress/e2e/data_sources @elastic/security-detection-engine
+/x-pack/test/security_solution_cypress/cypress/e2e/detection_alerts @elastic/security-detection-engine
+/x-pack/test/security_solution_cypress/cypress/e2e/detection_response/rule_actions @elastic/security-detection-engine
 /x-pack/test/security_solution_cypress/cypress/e2e/detection_response/rule_creation @elastic/security-detection-engine
 /x-pack/test/security_solution_cypress/cypress/e2e/detection_response/value_lists @elastic/security-detection-engine
 /x-pack/test/security_solution_cypress/cypress/e2e/entity_analytics @elastic/security-detection-engine