Enable automatic formatting for `sphinx/ext/linkcode.py`

.ruff.toml

@@ -415,7 +415,6 @@ exclude = [
     "sphinx/domains/python/_object.py",
     "sphinx/domains/rst.py",
     "sphinx/domains/std/__init__.py",
-    "sphinx/ext/linkcode.py",
     "sphinx/ext/todo.py",
     "sphinx/ext/viewcode.py",
 ]

sphinx/ext/linkcode.py

@@ -19,7 +19,7 @@ if TYPE_CHECKING:
 
 
 class LinkcodeError(SphinxError):
-    category = "linkcode error"
+    category = 'linkcode error'
 
 
 def doctree_read(app: Sphinx, doctree: Node) -> None: