Update keywords

array is obsolete, readonly is a new keyword, and the record feature
didn't leave experimental status.

Author: Wilfred

hack-mode.el

@@ -612,15 +612,14 @@ If PROPERTIZE-TAGS is non-nil, apply `hack-xhp-tag' to tag names."
      "concurrent"
      "enum"
      "newtype"
-     "record"
+     "readonly"
      "shape"
      "super"
      "tuple"
      "type"
      "where"
 
      ;; These contextual keywords are also used for literals, so highlight them as keywords.
-     "array"
      "darray"
      "dict"
      "keyset"