diff --git a/.ruff.toml b/.ruff.toml
index 155dd07bd2f..af6d2608148 100644
--- a/.ruff.toml
+++ b/.ruff.toml
@@ -415,7 +415,6 @@ exclude = [
     "sphinx/domains/python/_object.py",
     "sphinx/domains/rst.py",
     "sphinx/domains/std/__init__.py",
-    "sphinx/ext/githubpages.py",
     "sphinx/ext/graphviz.py",
     "sphinx/ext/ifconfig.py",
     "sphinx/ext/imgconverter.py",
diff --git a/sphinx/ext/githubpages.py b/sphinx/ext/githubpages.py
index aac47975a14..8aec8b77efb 100644
--- a/sphinx/ext/githubpages.py
+++ b/sphinx/ext/githubpages.py
@@ -43,8 +43,8 @@ def create_nojekyll_and_cname(app: Sphinx, env: BuildEnvironment) -> None:
 
     domain = _get_domain_from_url(app.config.html_baseurl)
     # Filter out GitHub Pages domains, as they do not require CNAME files.
-    if domain and not domain.endswith(".github.io"):
-        with open(cname_path, 'w', encoding="utf-8") as f:
+    if domain and not domain.endswith('.github.io'):
+        with open(cname_path, 'w', encoding='utf-8') as f:
             # NOTE: don't write a trailing newline. The `CNAME` file that's
             # auto-generated by the GitHub UI doesn't have one.
             f.write(domain)