Merge pull request #1736 from alphagov/dependabot/bundler/mongo-2.19.3

Bump mongo from 2.19.2 to 2.19.3

Author: ryanb-gds

Gemfile.lock

@@ -244,7 +244,7 @@ GEM
     mini_mime (1.1.5)
     mini_portile2 (2.8.5)
     minitest (5.20.0)
-    mongo (2.19.2)
+    mongo (2.19.3)
       bson (>= 4.14.1, < 5.0.0)
     mongoid (8.1.3)
       activemodel (>= 5.1, < 7.2, != 7.0.0)