tools: fix updating root certificates
When searching for the latest certdata.txt, check that the file exists on the remote server.
Refs: https://github.com/nodejs/node/issues/47597#issuecomment-1512506959
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
When searching for the latest certdata.txt, check that the file exists on the remote server.
Refs: https://github.com/nodejs/node/issues/47597#issuecomment-1512506959