Reduce the complexity of other/graham_scan.py (#7953)

* Reduce the complexity of other/graham_scan.py

* Lower the --max-complexity threshold in the file .flake8

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

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

* Fix tests

* Update other/graham_scan.py

Co-authored-by: Christian Clauss <[email protected]>

* Update graham_scan.py

* Update other/graham_scan.py

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