Merge pull request #275 from mruby/dependabot/bundler/json-2.19.9

Bump json from 2.19.3 to 2.19.9

Author: matz

Gemfile.lock

@@ -62,7 +62,7 @@ GEM
       jekyll (>= 3.7, < 5.0)
     jekyll-watch (2.2.1)
       listen (~> 3.0)
-    json (2.19.3)
+    json (2.19.9)
     kramdown (2.5.2)
       rexml (>= 3.4.4)
     kramdown-parser-gfm (1.1.0)