feat(cli): add DataDog Go tracer (#9411)

cli/server.go

@@ -2105,6 +2105,7 @@ func ConfigureTraceProvider(
 		sdkTracerProvider, _closeTracing, err := tracing.TracerProvider(ctx, "coderd", tracing.TracerOpts{
 			Default:   cfg.Trace.Enable.Value(),
 			Coder:     shouldCoderTrace,
+			DataDog:   cfg.Trace.DataDog.Value(),
 			Honeycomb: cfg.Trace.HoneycombAPIKey.String(),
 		})
 		if err != nil {

cli/testdata/server-config.yaml.golden

@@ -201,6 +201,9 @@ introspection:
     # which may incur significant costs.
     # (default: <unset>, type: bool)
     captureLogs: false
+    # Enables sending Go runtime traces to the local DataDog agent.
+    # (default: false, type: bool)
+    dataDog: false
   logging:
     # Output debug-level logs.
     # (default: <unset>, type: bool)