[MNT] ruff linting - allow use of assert (S101) (#1701)

Currently, pre-commit trips over uses of `assert` which exist in
non-test code across the code base.

This is often discouraged, but a de-facto part of the current code base,
so for now we should simply skip the corresponding linting rule.

pyproject.toml

@@ -22,6 +22,7 @@ extend-ignore = [
   "C408", # Unnecessary dict call - rewrite as a literal.
   "C409", # Unnecessary list passed to tuple() - rewrite as a tuple literal.
   "F401", # unused imports
+  "S101", # use of assert
 ]
 
 [tool.ruff.lint.isort]