DEV: upgrade mini_sql (#12465)

* DEV: upgrade mini_sql

Even though we are not planning on using this quite yet, mini_sql now supports
prepared statements.

Would like this upgrade merged so we can do some benchmarking.

Note, this will not work with pg_bouncer, but sites that are not using it
may benefit from the feature.

* implement multisite friendly prepared statements

spec/lib/mini_sql_multisite_connection_spec.rb

@@ -73,6 +73,11 @@ describe MiniSqlMultisiteConnection do
       expect(outputString).to eq("123")
     end
 
+    it "supports prepared statements" do
+      DB.prepared.query("SELECT ?", 1)
+      DB.prepared.query("SELECT ?", 2)
+    end
+
   end
 
 end