rm unnecessary widenconst_bestguess call (#38871)

the equivalent widening logic is imposed within `typeinf_local`,
and so as far as I understand we don't this need `widenconst_bestguess`
in `typeinf_edge`

(cherry picked from commit 341d6c9)

base/compiler/typeinfer.jl

@@ -759,20 +759,15 @@ function typeinf_edge(interp::AbstractInterpreter, method::Method, @nospecialize
         end
         typeinf(interp, frame)
         update_valid_age!(frame, caller)
-        return widenconst_bestguess(frame.bestguess), frame.inferred ? mi : nothing
+        return frame.bestguess, frame.inferred ? mi : nothing
     elseif frame === true
         # unresolvable cycle
         return Any, nothing
     end
     # return the current knowledge about this cycle
     frame = frame::InferenceState
     update_valid_age!(frame, caller)
-    return widenconst_bestguess(frame.bestguess), nothing
-end
-
-function widenconst_bestguess(bestguess)
-    !isa(bestguess, Const) && !isa(bestguess, PartialStruct) && !isa(bestguess, Type) && return widenconst(bestguess)
-    return bestguess
+    return frame.bestguess, nothing
 end
 
 #### entry points for inferring a MethodInstance given a type signature ####