Revert of "Implement the inert attribute"

third_party/WebKit/Source/core/html/HTMLAttributeNames.json5

 {
   metadata: {
     namespace: "HTML",
     namespacePrefix: "xhtml",
     namespaceURI: "http://www.w3.org/1999/xhtml",
     attrsNullNamespace: true,
     export: "CORE_EXPORT",
   },
 
   data: [
@@ skipping 128 matching lines @@
     "height",
     "hidden",
     "high",
     "href",
     "hreflang",
     "hspace",
     "http-equiv",
     "icon",
     "id",
     "incremental",
-    "inert",
     "inputmode",
     "integrity",
     "is",
     "ismap",
     "keytype",
     "kind",
     "label",
     "lang",
     "language",
     "leftmargin",
@@ skipping 188 matching lines @@
     "value",
     "valuetype",
     "version",
     "vlink",
     "vspace",
     "webkitdirectory",
     "width",
     "wrap",
   ],
 }