Use Go 1.22 unalias (#3471)

Signed-off-by: Steve Coffman <steve@khanacademy.org>

codegen/config/binder.go

@@ -258,7 +258,7 @@ func (ref *TypeReference) IsPtrToSlice() bool {
 
 func (ref *TypeReference) IsPtrToIntf() bool {
 	if ref.IsPtr() {
-		_, isPointerToInterface := ref.GO.(*types.Pointer).Elem().(*types.Interface)
+		_, isPointerToInterface := types.Unalias(ref.GO.(*types.Pointer).Elem()).(*types.Interface)
 		return isPointerToInterface
 	}
 	return false

internal/code/alias.go

@@ -1,13 +1,17 @@
-//go:build !go1.23
-
 package code
 
 import (
 	"go/types"
 )
 
 // Unalias unwraps an alias type
-// TODO: Drop this function when we drop support for go1.22
 func Unalias(t types.Type) types.Type {
-	return t // No-op
+	if p, ok := t.(*types.Pointer); ok {
+		// If the type come from auto-binding,
+		// it will be a pointer to an alias type.
+		// (e.g: `type Cursor = entgql.Cursor[int]`)
+		// *ent.Cursor is the type we got from auto-binding.
+		return types.NewPointer(Unalias(p.Elem()))
+	}
+	return types.Unalias(t)
 }