Add mypy config

Author: holtskinner

.github/workflows/linter.yaml

@@ -63,4 +63,5 @@ jobs:
           VALIDATE_TYPESCRIPT_STANDARD: false
           VALIDATE_GIT_COMMITLINT: false
           MARKDOWN_CONFIG_FILE: .markdownlint.json
+          PYTHON_MYPY_CONFIG_FILE: .mypy.ini
           FILTER_REGEX_EXCLUDE: '^examples/.*'