Update codeowner test

Author: viduni94

src/platform/packages/private/kbn-code-owners/src/code_owner_areas.test.ts

@@ -59,6 +59,7 @@ const LEGACY_CODE_OWNER_AREA_MAPPINGS: { [area in CodeOwnerArea]: string[] } = {
     'elastic/actionable-obs-team',
     'elastic/apm-agent-approvers',
     'elastic/nightshift-context-and-research-team',
+    'elastic/nightshift-investigations-team',
     'elastic/nightshift-sre-agent-team',
     'elastic/obs-cloudnative-monitoring',
     'elastic/obs-docs',