Respect isolated mode in the asyncio REPL

Author: johnslavik

Lib/asyncio/__main__.py

@@ -95,7 +95,7 @@ def run(self):
 
             console.write(banner)
 
-            if startup_path := os.getenv("PYTHONSTARTUP"):
+            if not sys.flags.isolated and (startup_path := os.getenv("PYTHONSTARTUP")):
                 sys.audit("cpython.run_startup", startup_path)
 
                 import tokenize