Don't trace async.task unless there is an active trace.

- Prevent a ton of trace garbage / incorrect/irrelevant parenting.

async.gemspec

@@ -27,5 +27,7 @@ Gem::Specification.new do |spec|
 
 	spec.add_dependency "console", "~> 1.29"
 	spec.add_dependency "fiber-annotation"
-	spec.add_dependency "io-event", ["~> 1.6", ">= 1.6.5"]
+	spec.add_dependency "io-event", "~> 1.7"
+	spec.add_dependency "traces", "~> 0.15"
+	spec.add_dependency "metrics", "~> 0.12"
 end

gems.rb

@@ -25,9 +25,6 @@
 	gem "decode"
 	gem "rubocop"
 
-	gem "traces"
-	gem "metrics"
-
 	gem "sus-fixtures-async"
 	gem "sus-fixtures-console"
 	gem "sus-fixtures-time"

lib/traces/provider/async/task.rb

@@ -8,6 +8,11 @@
 
 Traces::Provider(Async::Task) do
 	def schedule(&block)
+		# If we are not actively tracing anything, then we can skip this:
+		unless Traces.active?
+			return super(&block)
+		end
+
 		unless self.transient?
 			trace_context = Traces.trace_context
 		end
@@ -18,6 +23,7 @@ def schedule(&block)
 			"transient" => self.transient?,
 		}
 
+		# Run the trace in the context of the child task:
 		super do
 			Traces.trace_context = trace_context
 
@@ -26,6 +32,7 @@ def schedule(&block)
 			end
 
 			Traces.trace("async.task", attributes: attributes) do
+				# Yes, this is correct, we already called super above:
 				yield
 			end
 		end