[BUG] Stack traces are reported for ALL spans (< 5 ms)

[z1c0]

APM Agent version

1.19.0

Environment

https://release-oblt.kb.us-west2.gcp.elastic-cloud.com/app/home#/

Describe the bug

All dotnet spans in this environment have stack trace data.
There is no evidence of SpanStackTraceMinDuration being configured, so spans with a duration below 5ms should
not report a stack trace.

To Reproduce

Here is an example of such a span (look at the JSON tab).

So far, the behavior could not be reproduced in a local dev environment.

Note: All dotnet spans in the environment where the problem occurs are of span.type = db, span.subtype = sqlite. This could be a clue.

Also, see this Slack thread

[gregkalapos]

There is an optional parameter to capture the stacktrace when the span is started (this is due to `async): https://github.com/elastic/apm-agent-dotnet/blob/main/src/Elastic.Apm/Model/Span.cs#LL68

We do that in EFCore instrumentation: https://github.com/elastic/apm-agent-dotnet/blob/main/src/Elastic.Apm.EntityFrameworkCore/EfCoreDiagnosticListener.cs#L41

But I wonder if we remove those if the span is less than the SpanStackTraceMinDuration 🤔 I don't think so... shouldn't it be here? https://github.com/elastic/apm-agent-dotnet/blob/main/src/Elastic.Apm/Model/Span.cs#L471