[GR-8924] Switch to native json

PullRequest: truffleruby/741

Author: chrisseaton

CHANGELOG.md

@@ -20,6 +20,7 @@ Changes:
 * The Trufle handle patches applied to `psych` C extension have now been removed.
 * The `rb_tr_handle_*` functions have been removed as they are no
   longer used in any C extension patches.
+* The native version of `json` is now being used.
 
 Bug fixes:
 

doc/contributor/updating-ruby.md

@@ -49,11 +49,6 @@ You'll usually get some conflicts to work out.
 * Update `doc/legal/legal.md`
 * Update `doc/contributor/stdlib.md`
 
-## Update libraries from third-party repos
-
-Look in `../ruby/ext/json` to see the version of `flori/json` being used, and
-then copy the original source of `flori/json` into `lib/json`.
-
 ## Updating .gemspec of default gems
 
 Default gems are imported from MRI files, except the .gemspec files in