fix: explicitly define property for entity relation as enumerable (typeorm#9437)

In some environments it seems like entity object was created with columns values set to undefined, thus Object.defineProperty uses already defined value for enumerable - true.
    Which leads to RawSqlResultsToEntityTransformer.transform() run getters on relation fields (as they were enumerable) resolving the promises - running queries which eventually leads to the Free memory exhaustion on the machine :)

    Closes: typeorm#6631

Author: orcwarrior

src/query-builder/RelationLoader.ts

@@ -448,6 +448,7 @@ export class RelationLoader {
                 }
             },
             configurable: true,
+            enumerable: false,
         })
     }
 }