Remove old context prototype (#8162)

Author: mcculls

dd-trace-core/src/main/java/datadog/trace/core/DDBaggage.java

@@ -9,7 +9,7 @@
 import java.util.List;
 import java.util.Map;
 
-public interface AgentSpan extends MutableSpan, IGSpanInfo, ImplicitContextKeyed, WithAgentSpan {
+public interface AgentSpan extends MutableSpan, IGSpanInfo, WithAgentSpan {
 
   DDTraceId getTraceId();
 
@@ -141,11 +141,6 @@ public interface AgentSpan extends MutableSpan, IGSpanInfo, ImplicitContextKeyed
 
   void addLink(AgentSpanLink link);
 
-  @Override
-  default ScopedContext storeInto(ScopedContext context) {
-    return context.with(ScopedContextKey.SPAN_KEY, this);
-  }
-
   AgentSpan setMetaStruct(final String field, final Object value);
 
   boolean isOutbound();