[Code Clean] Remove deadcodes about Python3.9 [5/N] (pytorch#163644)

As the title stated.
Pull Request resolved: pytorch#163644
Approved by: https://github.com/jansel
ghstack dependencies: pytorch#163626, pytorch#163627, pytorch#163629, pytorch#163643

Author: fffrog

tools/linter/adapters/import_linter.py

@@ -47,7 +47,7 @@ class LintMessage(NamedTuple):
 CURRENT_FILE_NAME = os.path.basename(__file__)
 _MODULE_NAME_ALLOW_LIST: set[str] = set()
 
-# Add builtin modules.
+# Add builtin modules of python.
 _MODULE_NAME_ALLOW_LIST.update(sys.stdlib_module_names)
 
 # Add the allowed third party libraries. Please avoid updating this unless you