Bump mini_racer from 0.4.0 to 0.6.0

Bumps [mini_racer](https://github.com/discourse/mini_racer) from 0.4.0 to 0.6.0.
- [Release notes](https://github.com/discourse/mini_racer/releases)
- [Changelog](https://github.com/rubyjs/mini_racer/blob/master/CHANGELOG)
- [Commits](https://github.com/discourse/mini_racer/compare/v0.4.0...v0.6.0)

---
updated-dependencies:
- dependency-name: mini_racer
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile

@@ -2,7 +2,7 @@ source 'https://rubygems.org'
 # gem 'github-pages', group: :jekyll_plugins
 gem 'activesupport'
 gem "actionview", ">= 5.2.4.2"
-gem 'mini_racer', "< 0.5.0"
+gem 'mini_racer', "< 0.7.0"
 # gem 'github-pages-health-check'
 gem 'html-proofer', group: :development
 gem 'jekyll', '~> 4.2'

Gemfile.lock

@@ -136,7 +136,7 @@ GEM
       rexml
     kramdown-parser-gfm (1.1.0)
       kramdown (~> 2.0)
-    libv8-node (15.14.0.1)
+    libv8-node (16.10.0.0)
     liquid (4.0.3)
     listen (3.7.0)
       rb-fsevent (~> 0.10, >= 0.10.3)
@@ -147,8 +147,8 @@ GEM
     mercenary (0.4.0)
     method_source (1.0.0)
     mini_portile2 (2.6.1)
-    mini_racer (0.4.0)
-      libv8-node (~> 15.14.0.0)
+    mini_racer (0.6.0)
+      libv8-node (~> 16.10.0.0)
     minima (2.5.1)
       jekyll (>= 3.5, < 5.0)
       jekyll-feed (~> 0.9)
@@ -253,7 +253,7 @@ DEPENDENCIES
   listen
   loofah (>= 2.3.1)
   mercenary
-  mini_racer (< 0.5.0)
+  mini_racer (< 0.7.0)
   minima
   nokogiri (>= 1.10.4)
   rack (~> 2.2.3)