Bump mini_racer from 0.4.0 to 0.5.0

Bumps [mini_racer](https://github.com/discourse/mini_racer) from 0.4.0 to 0.5.0.
- [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...v0.5.0)

---
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.lock

@@ -136,7 +136,7 @@ GEM
       rexml
     kramdown-parser-gfm (1.1.0)
       kramdown (~> 2.0)
-    libv8-node (15.14.0.0)
+    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 (0.5.0)
+      libv8-node (~> 16.10.0.0)
     minima (2.5.1)
       jekyll (>= 3.5, < 5.0)
       jekyll-feed (~> 0.9)