chore: udpate examples

Author: future-xy

examples/foo.py

@@ -1,4 +1,5 @@
 import time
+
 print("hello world")
 while True:
-  time.sleep(1)
+    time.sleep(1)

examples/start_vllm.py

@@ -11,6 +11,7 @@
 """
 
 import httpx
+
 import pylet
 
 
@@ -41,7 +42,7 @@ def main():
     # 3. Wait for vLLM to be ready (model loading takes time)
     print("Waiting for vLLM to load model...")
     with httpx.Client(timeout=300) as http:
-        for attempt in range(60):  # up to 5 minutes
+        for _attempt in range(60):  # up to 5 minutes
             try:
                 resp = http.get(f"http://{instance.endpoint}/v1/models")
                 if resp.status_code == 200:
@@ -50,6 +51,7 @@ def main():
             except httpx.ConnectError:
                 pass
             import time
+
             time.sleep(5)
         else:
             print("Timeout waiting for vLLM")