Fix minor typing errors in maths/

[CaedenPH]

Describe your change:

Some changes include:

• Replacing all occurrences of np.array types with np.ndarray, the class returned from np.array
• Typing certain function bodies
• Refactoring jaccard_similarity to include types and fix mypy errors (bug) that stored types from variables from different scopes

maths\jaccard_similarity.py:80: error: Incompatible types in assignment (expression has type "list[str]", variable has type "int")  [assignment]
maths\jaccard_similarity.py:84: error: Argument 1 to "len" has incompatible type "int"; expected "Sized"  [arg-type]
maths\jaccard_similarity.py:87: error: Incompatible types in assignment (expression has type "list[str]", variable has type "int")  [assignment]
maths\jaccard_similarity.py:88: error: Argument 1 to "len" has incompatible type "int"; expected "Sized"  [arg-type]

• Fixed jaccard_similarity and added doctests to prove fixes

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

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 description above includes the issue number(s) with a closing keyword: "Fixes #ISSUE-NUMBER".

[tianyizheng02]

Overall good fixes, definitely helps to fix many of the mypy errors I reported in #8070