misc/makerelease: handle update tour file layout

Fixes #7835.

LGTM=bradfitz
R=golang-codereviews, bradfitz
CC=golang-codereviews
https://golang.org/cl/94670044

misc/makerelease/makerelease.go

@@ -91,7 +91,6 @@ var tourPackages = []string{
 
 var tourContent = []string{
 	"content",
-	"js",
 	"solutions",
 	"static",
 	"template",