Better support for OpenTelemetry.

- Prefer to use `Traces.current_context` and `Traces.with_context`.

Author: ioquatix

async.gemspec

@@ -29,5 +29,5 @@ Gem::Specification.new do |spec|
 	spec.add_dependency "fiber-annotation"
 	spec.add_dependency "io-event", "~> 1.11"
 	spec.add_dependency "metrics", "~> 0.12"
-	spec.add_dependency "traces", "~> 0.15"
+	spec.add_dependency "traces", "~> 0.18"
 end

lib/traces/provider/async/task.rb

@@ -14,7 +14,7 @@ def schedule(&block)
 		end
 
 		unless self.transient?
-			trace_context = Traces.trace_context
+			trace_context = Traces.current_context
 		end
 
 		attributes = {
@@ -25,7 +25,7 @@ def schedule(&block)
 
 		# Run the trace in the context of the child task:
 		super do
-			Traces.trace_context = trace_context
+			Traces.with_context(trace_context)
 
 			if annotation = self.annotation
 				attributes["annotation"] = annotation