Increase timeout once again. (#5021)

When failpoint is early in deletion process it takes longer to complete
after failpoint is removed.

Example was: https://neon-github-public-dev.s3.amazonaws.com/reports/main/5889544346/index.html#suites/3556ed71f2d69272a7014df6dcb02317/49826c68ce8492b1

test_runner/fixtures/pageserver/utils.py

@@ -315,4 +315,4 @@ def tenant_delete_wait_completed(
 
 
 def poll_for_remote_storage_iterations(remote_storage_kind: RemoteStorageKind) -> int:
-    return 30 if remote_storage_kind is RemoteStorageKind.REAL_S3 else 10
+    return 40 if remote_storage_kind is RemoteStorageKind.REAL_S3 else 10