Add clean up in "always" phase of the block

Because our tests use --retry-on-error, and the first thing the test
does is to try to create the database. We must cleanup otherwise if
there is a retry, it will throw a misleading "database already exists"
error.

tests/integration/targets/test_mysql_query/tasks/mysql_query_initial.yml

@@ -390,3 +390,10 @@
       that:
         - result is changed
         - result.executed_queries == ['DROP DATABASE {{ test_db }}']
+
+  always:
+
+    - name: Clean up test_db
+      mysql_query:
+        <<: *mysql_params
+        query: 'DROP DATABASE IF EXISTS {{ test_db }}'