fix: mypy 0.991 issues

[dhruvmanila]

fixes: #7987

Note that matrix/matrix_class.py had CRLF line endings, that was converted to LF line endings and that's the major diff you're seeing. The actual diff is:

diff --git a/matrix/matrix_class.py b/matrix/matrix_class.py
index a73e8b92..2b4edc3c 100644
--- a/matrix/matrix_class.py
+++ b/matrix/matrix_class.py
@@ -345,7 +345,7 @@ class Matrix:
         if other == 0:
             return self.identity()
         if other < 0:
-            if self.is_invertable:
+            if self.is_invertable():
                 return self.inverse() ** (-other)
             raise ValueError(
                 "Only invertable matrices can be raised to a negative power"

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}.

[CaedenPH]

Looks good but very odd diff's

[dhruvmanila]

Looks good but very odd diff's

diff reason is specified in the PR description :)

[cclauss]

thx!!