Add ruff to Pipfile

Author: tleonhardt

Pipfile

@@ -21,6 +21,7 @@ pyreadline3 = { version = ">=3.4", sys_platform = "== 'win32'" }
 pytest = "*"
 pytest-cov = "*"
 pytest-mock = "*"
+ruff = "*"
 sphinx = "*"
 sphinx-autobuild = "*"
 sphinx-rtd-theme = "*"