Drop Intl.displaynames and Intl.Segmenter, merged in Ecma402 (#481)

* Drop Intl.displayNames v2 proposal, merged in Ecma402

Proposal reached stage 4, was integrated in Ecma402 and now returns a 404:
tc39/proposals@f4378e1
tc39/ecma402#622

* Drop Intl.Segmenter proposal, merged in Ecma402

Proposal moved to stage 4, and was merged in Ecma402:
tc39/proposals@24bdab7
tc39/ecma402#553

specs.json

@@ -107,13 +107,6 @@
       ]
     }
   },
-  {
-    "url": "https://tc39.es/intl-displaynames-v2/",
-    "shortname": "tc39-intl-displaynames-v2",
-    "series": {
-      "shortname": "tc39-intl-displaynames"
-    }
-  },
   "https://tc39.es/proposal-accessible-object-hasownproperty/",
   "https://tc39.es/proposal-array-find-from-last/",
   "https://tc39.es/proposal-array-grouping/",
@@ -126,7 +119,6 @@
   "https://tc39.es/proposal-intl-enumeration/",
   "https://tc39.es/proposal-intl-extend-timezonename/",
   "https://tc39.es/proposal-intl-locale-info/",
-  "https://tc39.es/proposal-intl-segmenter/",
   "https://tc39.es/proposal-json-modules/",
   "https://tc39.es/proposal-private-fields-in-in/",
   "https://tc39.es/proposal-private-methods/",