Update release verification script for now PyPi API (#31007)

tools/release/verify_python_release.py

@@ -71,9 +71,11 @@ def _get_remote_artifacts_for_package(package, version):
     experience, it has taken a minute on average to be fresh.
     """
     artifacts = set()
-    payload = requests.get("https://pypi.org/pypi/{}/{}/json".format(
+    payload_resp = requests.get("https://pypi.org/pypi/{}/{}/json".format(
-        package, version)).json()
+        package, version))
-    for download_info in payload['releases'][version]:
+    payload_resp.raise_for_status()
+    payload = payload_resp.json()
+    for download_info in payload['urls']:
         artifacts.add(
             Artifact(download_info['filename'], download_info['md5_digest']))
     return artifacts