[data] Update spec info

Author: fetch-info bot

index.json

@@ -20765,7 +20765,7 @@
     ],
     "release": {
       "url": "https://www.w3.org/TR/mathml4/",
-      "status": "First Public Working Draft",
+      "status": "Working Draft",
       "filename": "Overview.html"
     },
     "nightly": {