Update latest.txt for 4.0.4 release

scripts/latest.txt

@@ -1,6 +1,6 @@
 {
-    "version": "4.0.1",
-    "url":     "https://docs.wagtail.org/en/stable/releases/4.0.1.html",
+    "version": "4.0.4",
+    "url":     "https://docs.wagtail.org/en/stable/releases/4.0.4.html",
     "minorUrl": "https://docs.wagtail.org/en/stable/releases/4.0.html",
     "lts": {
         "version": "2.15.6",