fix typo graphs/greedy_best_first.py

[JadeKim042386]

Fixes #8764

Describe your change:

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Documentation change?

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new Python files are placed inside an existing directory.
• All filenames are in all lowercase characters with no spaces or dashes.
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms include at least one URL that points to Wikipedia or another similar explanation.
• If this pull request resolves one or more open issues then the commit message contains Fixes: #{$ISSUE_NO}.

[JadeKim042386]

@cclauss @tianyizheng02 For subsequent contributions and fix failing build tests, #8763 must be reflected.

FAILED web_programming/fetch_anime_and_play.py::web_programming.fetch_anime_and_play.get_anime_episode
FAILED web_programming/fetch_anime_and_play.py::web_programming.fetch_anime_and_play.search_anime_episode_list
FAILED web_programming/fetch_anime_and_play.py::web_programming.fetch_anime_and_play.search_scraper

[tianyizheng02]

Good catch!