cache_s3 outputs misleading 404 message (from aws.s3::head_object) for new keys. #96
Description
In cache_s3's cache_has_key uses aws.s3::head_object (ref), which outputs a message Client error: (404) Not Found when the key does not exist yet.
These messages spam the logs/outputs, which can be a bit misleading, as they are somewhat expected behaviour.
It would be nice to suppress this message in some way, for example by implementing a "better" version of aws.s3::head_object or simply using suppressMessages (which seems to be used for the gcs variant).