Added Johnson's algorithm for all-pairs shortest paths (#13340)

* Fix typos in Johnson's algorithm (nd -> and) to pass codespell

* Rename type aliases and h parameter to follow snake_case and descriptive naming

* Potential fix for pull request finding

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

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Co-authored-by: John Law <johnlaw.po@gmail.com>
Co-authored-by: Christian Clauss <cclauss@me.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>