fix(api): AWSGraphQLSubscriptionTaskRunner failing to cancel AppSyncRealTimeSubscription

[almasios]

Description

Amplify fails to cancel/deallocate AppSyncRealTimeSubscription because AWSGraphQLSubscriptionTaskRunner gets released before it has a chance to tell AppSyncRealTimeClient to unsubscribe the subscription.
If you keep cancelling and creating new subscriptions (for example when you minimize and open the app) at some point the number of active subscriptions reaches 100 and the app starts to crash.

edit:

• this is reproducible in 2.29.1

General Checklist

• Added new tests to cover change, if needed
• Build succeeds with all target using Swift Package Manager
• All unit tests pass
• All integration tests pass
• Security oriented best practices and standards are followed (e.g. using input sanitization, principle of least privilege, etc)
• Documentation update for the change if required
• PR title conforms to conventional commit style
• New or updated tests include Given When Then inline code documentation and are named accordingly testThing_condition_expectation()
• If breaking change, documentation/changelog update with migration instructions

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[5d]

Thanks for contributing, @almasios. Can you please specify the version with which you're encountering this issue in the description?

[almasios]

Thanks for contributing, @almasios. Can you please specify the version with which you're encountering this issue in the description?

@5d this is using latest 2.29.1

[5d]

Thank you, we'll look into this and get back to you after it.

[5d]

LGTM