Issue #16537: Use the new *default* parameter of max().

setup.py

@@ -263,9 +263,7 @@ class PyBuildExt(build_ext):
         for ext in self.extensions:
             self.check_extension_import(ext)
 
-        longest = 0
-        if self.extensions:
-            longest = max([len(e.name) for e in self.extensions])
+        longest = max([len(e.name) for e in self.extensions], default=0)
         if self.failed or self.failed_on_import:
             all_failed = self.failed + self.failed_on_import
             longest = max(longest, max([len(name) for name in all_failed]))