Check for usages of deprecated using the type checker (#284)

Author: johnthagen

pyproject.toml

@@ -82,9 +82,7 @@ default-groups = "all"
 [tool.mypy]
 ignore_missing_imports = true
 strict = true
-# TODO: Remove this when explicit-override is enabled by default in strict mode
-#   https://github.com/python/mypy/issues/17511
-enable_error_code = ["explicit-override"]
+enable_error_code = ["deprecated", "explicit-override"]
 # If certain strict config options are too pedantic for a project,
 # disable them selectively here by setting to false.