…scanned languages.

In theory, a scanned language will not setup the build tracer, and so
shouldn't care about lua versus legacy tracing. However, `go` is a
special case where the autobuilder runs under the build tracer, that
then gets disabled immediately again, unless a special environment
variable is used.
Therefore, we need to thread through the feature flag to this
`database trace-command` invocation. For other scanned languages,
this should be a no-op, as no tracing is ever set up.