chore: remove replace directive to DataDog/datadog-go because version was retracted and fixed (#3905)

Author: eliottness

go.mod

@@ -6,8 +6,6 @@ godebug x509negativeserial=1
 
 replace github.com/DataDog/datadog-agent/pkg/trace => github.com/DataDog/datadog-agent/pkg/trace v0.67.0
 
-replace github.com/DataDog/datadog-go/v5 => github.com/DataDog/datadog-go/v5 v5.6.0
-
 require (
 	github.com/DataDog/appsec-internal-go v1.13.0
 	github.com/DataDog/datadog-agent/pkg/obfuscate v0.67.0