useContextValuePerExecuteSubscriptionEvent: Spread operator fails to merge objects when contextValue is a class

[abhip167]

Issue workflow progress

Describe the bug

• A spread operator is being used to merge the previous context and the new context. If the context is a class and there are methods in its prototype, it will lose the prototype methods during this merging.
• Code from https://github.com/n1ru4l/envelop/blob/main/packages/plugins/execute-subscription-event/src/index.ts

onSubscribe({ args, setSubscribeFn }) {
     const executeNew = makeExecute(async executionArgs => {
       const context = await createContext({ args });
       try {
         return await execute({
           ...executionArgs,
           // GraphQL.js 16 changed the type of contextValue to unknown
           // eslint-disable-next-line @typescript-eslint/ban-ts-comment
           // @ts-ignore
           contextValue: { ...executionArgs.contextValue, ...context?.contextPartial },
         });
       } finally {
         context?.onEnd?.();
       }
     });
     setSubscribeFn(subscribe(executeNew));
   },

Expected behavior

• The object's property should be replaced with a new value, rather than merging the objects using the spread operator.