Use any() to stub getSyntheticGlobalType

This is used in all other languages not currently using dataflow type
pruning.

Author: owen-mc

go/ql/lib/semmle/go/dataflow/internal/FlowSummaryImplSpecific.qll

@@ -56,7 +56,7 @@ DataFlowType getCallbackParameterType(DataFlowType t, ArgumentPosition pos) { an
 DataFlowType getCallbackReturnType(DataFlowType t, ReturnKind rk) { any() }
 
 /** Gets the type of synthetic global `sg`. */
-DataFlowType getSyntheticGlobalType(SummaryComponent::SyntheticGlobal sg) { none() }
+DataFlowType getSyntheticGlobalType(SummaryComponent::SyntheticGlobal sg) { any() }
 
 /**
  * Holds if an external flow summary exists for `c` with input specification