Stop depending on the mysql cookbook to install mysql-server

The mysql cookbook is completely broken on 18.04 (both the released version
and the current master, in different ways). Keep it simple and just run
mysql commands

Berksfile

@@ -4,7 +4,7 @@ source 'https://supermarket.chef.io'
 
 cookbook 'mediawiki',
          git: 'https://github.com/67P/mediawiki-cookbook.git',
-         ref: '70ae159e8ecc0c2a2d8d94465cc4211e8deb0eaa'
+         ref: '55a4680ee298199fa5f7fa51b5c589fbfa52eed0'
 cookbook 'redis',
          git: 'https://github.com/phlipper/chef-redis.git',
          ref: 'v0.5.6'

Berksfile.lock

@@ -25,8 +25,8 @@ DEPENDENCIES
   mariadb (= 0.3.1)
   mediawiki
     git: https://github.com/67P/mediawiki-cookbook.git
-    revision: 70ae159e8ecc0c2a2d8d94465cc4211e8deb0eaa
-    ref: 70ae159
+    revision: 55a4680ee298199fa5f7fa51b5c589fbfa52eed0
+    ref: 55a4680
   mysql (~> 8.5.1)
   mysql2_chef_gem (= 1.1.0)
   nginx (= 9.0.0)
@@ -107,10 +107,8 @@ GRAPH
     apt (>= 0.0.0)
     yum (>= 0.0.0)
     yum-epel (>= 0.0.0)
-  mediawiki (0.3.0)
+  mediawiki (0.5.0)
     apache2 (>= 0.0.0)
-    database (>= 0.0.0)
-    mysql (>= 0.0.0)
     nginx (>= 0.0.0)
     php (>= 0.0.0)
     php-fpm (>= 0.0.0)