This change enables the PrometheusRemoteWriteBehind alert’s expression to be evaluated
even when the remote endpoint has never been reached. As a result, PrometheusRemoteWriteBehind
will fire to easily detect configuration mistakes (such as incorrect endpoint URLs) or
unrecoverable connectivity issues.
See https://github.com/prometheus/prometheus/issues/14350 for details.
Signed-off-by: machine424 <ayoubmrini424@gmail.com>