don't connect destroyers to module expanders

Resource destroy nodes can only depend on other resources. Connecting
them to their module expander can introduce cycles when the module
expander depends on resources in the destroyer's subgraph.

terraform/transform_module_expansion.go

@@ -47,6 +47,7 @@ func (t *ModuleExpansionTransformer) Transform(g *Graph) error {
 		if _, ok := v.(*nodeCloseModule); ok {
 			continue
 		}
+
 		// any node that executes within the scope of a module should be a
 		// GraphNodeModulePath
 		pather, ok := v.(GraphNodeModulePath)
@@ -113,6 +114,10 @@ func (t *ModuleExpansionTransformer) transform(g *Graph, c *configs.Config, pare
 
 		var path addrs.Module
 		switch t := childV.(type) {
+		case GraphNodeDestroyer:
+			// skip destroyers, as they can only depend on other resources.
+			continue
+
 		case GraphNodeModulePath:
 			path = t.ModulePath()
 		case GraphNodeReferenceOutside: