Support for OTEL_SDK_DISABLED #4155
Description
Feature Request
Support for OTEL_SDK_DISABLED based on https://github.com/open-telemetry/opentelemetry-specification/blob/dd47c009da1de335c540decc5d5930e46ea61916/specification/sdk-environment-variables.md?plain=1#L71
Previous PR: #3639
Additional Context
Found while working on open-telemetry/opentelemetry-dotnet-instrumentation#2009