Report feature "resourceReferences" is not supported (#5709)

This feature isn't fully supported yet, so stop reporting it is.

CHANGELOG.md

@@ -2,7 +2,9 @@ CHANGELOG
 =========
 
 ## HEAD (Unreleased)
-_(none)_
+
+- Fix a bug that was causing errors when (de)serializing custom resources.
+  [#5709](https://github.com/pulumi/pulumi/pull/5709)
 
 ## 2.13.1 (2020-11-06)
 

pkg/resource/deploy/source_eval.go

@@ -532,7 +532,7 @@ func (rm *resmon) SupportsFeature(ctx context.Context,
 	hasSupport := false
 
 	switch req.Id {
-	case "secrets", "resourceReferences":
+	case "secrets":
 		hasSupport = true
 	}