poetry: Drop customizations.

Prepare for an updated Sphinx with a modern theme.

.vscode/extensions.json

@@ -5,9 +5,9 @@
 	// List of extensions which should be recommended for users of this workspace.
 	"recommendations": [
 		"ms-python.python",
-		"ms-python.black-formatter"
+		"charliermarsh.ruff"
 	],
 	// List of extensions recommended by VS Code that should not be recommended for users of this workspace.
 	"unwantedRecommendations": [
 	]
-}
+}

.vscode/settings.json

@@ -4,14 +4,9 @@
     },
     "python.defaultInterpreterPath": ".venv/bin/python",
     "python.autoComplete.extraPaths": ["jedi/src"],
-    "python.formatting.provider": "none",
-    "python.linting.pylintEnabled": false,
-    "python.linting.flake8Enabled": true,
-    "python.linting.pycodestyleEnabled": false,
-    "python.linting.enabled": true,
     "[python]": {
         "editor.formatOnSave": true,
-        "editor.defaultFormatter": "ms-python.black-formatter"
+        "editor.defaultFormatter": "charliermarsh.ruff"
     },
     "python.languageServer": "Pylance",
     "python.testing.pytestArgs": [