fix benchmark code (#8104)

## Summary of changes

signature changed in #7871, and since the benchmark CI step was broken
for another reason, I missed that.

## Reason for change

## Implementation details

## Test coverage

## Other details
<!-- Fixes #{issue} -->


<!--  ⚠️ Note:

Where possible, please obtain 2 approvals prior to merging. Unless
CODEOWNERS specifies otherwise, for external teams it is typically best
to have one review from a team member, and one review from apm-dotnet.
Trivial changes do not require 2 reviews.

MergeQueue is NOT enabled in this repository. If you have write access
to the repo, the PR has 1-2 approvals (see above), and all of the
required checks have passed, you can use the Squash and Merge button to
merge the PR. If you don't have write access, or you need help, reach
out in the #apm-dotnet channel in Slack.
-->

Author: vandonr

tracer/test/benchmarks/Benchmarks.Trace/AgentWriterBenchmark.cs

@@ -53,14 +53,14 @@ public void GlobalSetup()
 
             var api = new Api(
                 new FakeApiRequestFactory(settings.Manager.InitialExporterSettings.AgentUri),
-                new StatsdManager(settings, (_, _) => null!),
+                new StatsdManager(settings, (_, _, _) => null!),
                 ContainerMetadata.Instance,
                 updateSampleRates: null,
                 updateConfigState: null,
                 partialFlushEnabled: false,
                 healthMetricsEnabled: false);
 
-            var noOpStatsd = new StatsdManager(settings, (_, _) => null);
+            var noOpStatsd = new StatsdManager(settings, (_, _, _) => null);
             var noopApi = new NullApi();
             _agentWriter = new AgentWriter(api, statsAggregator: null, statsd: noOpStatsd, automaticFlush: false);
             _agentWriterNoOpFlush = new AgentWriter(noopApi, statsAggregator: null, statsd: noOpStatsd, automaticFlush: false);