Add typing to data_structures/heap/heap_generic.py (#7044)

* Update heap_generic.py

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* Update heap_generic.py

* Update heap_generic.py

* Update heap_generic.py

* Update heap_generic.py

* Update heap_generic.py

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>