CCM-11580: Remove hello world endpoint

Author: m-houston

lambdas/api-handler/src/handlers/__tests__/hello-world.test.ts

@@ -1,4 +1,3 @@
 // Export all handlers for ease of access
 export { getLetters } from './handlers/get-letters';
 export { patchLetters } from './handlers/patch-letters';
-export { helloWorld } from './handlers/hello-world';