Remove sampler arg env var logic once it is added to Sampler

[jeremydvoss]

Migrating from microsoft/ApplicationInsights-Python#264

See microsoft/ApplicationInsights-Python#262 for details

Currently, the Sampler object does not check the OTEL_TRACES_SAMPLER_ARG env var during initialization. Instead, the configuration layers above it -- configure_azure_monitor or autoinstrumentation -- check the env var and pass in a parsed value if appropriate. If we add this logic to the sampler object itself, we could remove it from the distro's configure_azure_monitor. However, we would need to keep that in the OTel-side autoinstrumentaiton logic no matter what. This change is mainly a design preference. However, if someone is using the piecemeal exporter approach, it would be a new configuration option.

[github-actions]

Hi @jeremydvoss, we deeply appreciate your input into this project. Regrettably, this issue has remained unresolved for over 2 years and inactive for 30 days, leading us to the decision to close it. We've implemented this policy to maintain the relevance of our issue queue and facilitate easier navigation for new contributors. If you still believe this topic requires attention, please feel free to create a new issue, referencing this one. Thank you for your understanding and ongoing support.