Fix Typehints in Task SDK

[kaxil]

Replaced the Type Hints which were either invalid or imported from Core -- to using SDK

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[potiuk]

5 approvals ! ... 1 merge :)

[Dev-iL]

I think these changes are related to the below issues reported on CI:

airflow-core/src/airflow/serialization/serialized_objects.py:1300: error: Argument 1 to "get_link" of "BaseOperatorLink" has incompatible type "SerializedBaseOperator"; expected "BaseOperator" 
[arg-type]
            return link.get_link(self.unmap(None), ti_key=ti.key)
                                 ^~~~~~~~~~~~~~~~

airflow-core/src/airflow/models/mappedoperator.py:168: error: Argument 1 to "get_link" of "BaseOperatorLink" has incompatible type "MappedOperator"; expected "BaseOperator"  [arg-type]
            return link.get_link(self, ti_key=ti.key)

[amoghrajesh]

@Dev-iL yep it seems to be related, I am on it