samples: add samples for partial list bucket (#1627)

Add samples for the partial list bucket feature.

---------

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: Pulkit0110

samples/snippets/storage_list_buckets_partial_success.py

@@ -0,0 +1,43 @@
+#!/usr/bin/env python
+
+# Copyright 2025 Google Inc. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the 'License');
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# [START storage_list_buckets_partial_success]
+from google.cloud import storage
+
+
+def list_buckets_with_partial_success():
+    """Lists buckets and includes unreachable buckets in the response."""
+
+    storage_client = storage.Client()
+
+    buckets_iterator = storage_client.list_buckets(return_partial_success=True)
+
+    for page in buckets_iterator.pages:
+        if page.unreachable:
+            print("Unreachable locations in this page:")
+            for location in page.unreachable:
+                print(location)
+
+        print("Reachable buckets in this page:")
+        for bucket in page:
+            print(bucket.name)
+
+
+# [END storage_list_buckets_partial_success]
+
+
+if __name__ == "__main__":
+    list_buckets_with_partial_success()