Bump agent to v-75e76ad (#721)
Bump agent to v-75e76ad (#721)

- Warn when adding an error to a child span
- Add debug logging for span event digests
- Only collect event metrics for slow span events
- Fix incidents not being emitted from Spans in certain cases
- Debug log entire transaction when event timestack is uneven

Note: The Ruby gem does not use the span API, but uses the transaction
API instead.
appsignal/appsignal-ruby,appsignal/appsignal-ruby,appsignal/appsignal-ruby,appsignal/appsignal-ruby