Added minimum waiting time problem solution using greedy algorithm (#8701)

* Added minimum waiting time problem solution using greedy algorithm

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

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

* ruff --fix

* Add type hints

* Added two more doc test

* Removed unnecessary comments

* updated type hints

* Updated the code as per the code review

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