Update CODEOWNERS

Author: aravindbuilt

.github/CODEOWNERS

@@ -1,5 +1 @@
-* @contentstack/devex-pr-reviewers
-.github/workflows/sca-scan.yml @contentstack/security-admin
-.github/workflows/sast-scan.yml @contentstack/security-admin
-.github/workflows/jira.yml @contentstack/security-admin
-**/.snyk @contentstack/security-admin
+* @contentstack/security-admin