When create_streaming_span_decorator is used in non-span-streaming mode, it emits a warning in the wrapper, then calls start_streaming_span() (which is sentry_sdk.traces.start_span). The start_span function also checks has_span_streaming_enabled() and emits its own warning. This results in two warnings being shown to the user for a single decorated function call, which is noisy and confusing. The decorator should either return early with an alternative execution path (similar to how traces.start_span returns NoOpStreamedSpan), or the warning should be emitted only in one place.

The decorator's async_wrapper and sync_wrapper emit a warning when span streaming is not enabled, then call start_streaming_span (aliased from traces.start_span), which also emits its own warning with a different message and returns a NoOpStreamedSpan. This results in two separate warnings being shown to users each time the decorated function is called without span streaming enabled.