fix(@nestjs/terminus): generate the correct openapi health schema

When generating the openapi documents 'status' is now marked as required then when generating a typescript client using openapi-generator it translates the healthcheck response to a correct interface. Otherwise the TS2411 compilation error appears.

lib/health-check/health-check.schema.ts

@@ -17,6 +17,7 @@ const healthIndicatorSchema = (example: HealthIndicatorResult) => ({
   example,
   additionalProperties: {
     type: 'object',
+    required: ['status'],
     properties: {
       status: {
         type: 'string',