Maintainance task - Potential breaking change!

Description

This issue aims to migrate from subscriptions-transport-ws to graphql-ws because the former is no longer maintained. This transition is crucial to ensure the ongoing reliability and performance of our GraphQL subscriptions. It involves adapting to the new subprotocol graphql-transport-ws, handling subscription closures, and thoroughly testing the new implementation with graphql-ws.

Additional information

Refer to the Apollo GraphQL Docs for more insights on utilizing graphql-ws for subscriptions and the subprotocol differences. This will introduce a breaking change, so it must be included in a major version bump.