Fix PR Preview (#516)

`Die On: warning` metadata even if valid causes PR Preview to fail

Author: anssiko

index.bs

@@ -20,7 +20,6 @@ Markup Shorthands: idl yes
 Markup Shorthands: css no
 Logo: https://webmachinelearning.github.io/webmachinelearning-logo.png
 Deadline: 2023-10-01
-Die On: warning
 Status Text: <p>
   Further implementation experience and user feedback is being gathered for the
   {{MLCommandEncoder}} interface that proposes to enable more efficient WebGPU