Update httpx code to follow redirects

A breaking change from awhile ago with httpx.

Author: mikeckennedy

apps/py/ch10_async/ascrape.py

@@ -21,7 +21,7 @@ async def get_html(n: int) -> str:
 
     # The "async with" syntax ensures that all active connections are closed on exit.
     async with httpx.AsyncClient() as client:
-        resp = await client.get(url)
+        resp = await client.get(url, follow_redirects=True)
         resp.raise_for_status()
 
     return resp.text