Add codeowner

Author: jsoriano

.github/CODEOWNERS

@@ -261,6 +261,7 @@
 /packages/hpe_aruba_cx @elastic/sec-deployment-and-devices
 /packages/hta @elastic/sec-applied-ml
 /packages/http_endpoint @elastic/security-service-integrations
+/packages/httpcheck @elatic/ecosystem
 /packages/httpjson @elastic/security-service-integrations
 /packages/ibmmq @elastic/obs-infraobs-integrations
 /packages/iis @elastic/obs-infraobs-integrations