Function normalize_dsc_for_span_data 

pub fn normalize_dsc_for_span_data(
    span_data: &mut Annotated<SpanData>,
    dsc: Option<EnrichedDsc<'_>>,
)

Writes DSC attributes needed for dynamic sampling into span_data.

If sentry.dsc.trace_id is already present in span_data, the function does nothing.