Fix ty invalid assignment (#15221)

* Fix ty invalid assignment diagnostics

* updating DIRECTORY.md

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

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* Fix unused typing import

* Fix gradient accumulation type handling

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

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* Fix automatic differentiation gradient dtype handling

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

Author: kadubhumika