Switch to safe theme before downgrading

Author: schlessera

features/language-core.feature

@@ -300,6 +300,7 @@ Feature: Manage translation files for a WordPress install
   @require-wp-4.0
   Scenario: Ensure correct language is installed for WP version
     Given a WP install
+    And I run `wp theme activate twentytwenty`
     And an empty cache
     And I run `wp core download --version=4.5.3 --force`
 
@@ -312,6 +313,7 @@ Feature: Manage translation files for a WordPress install
   @require-wp-4.0
   Scenario: Ensure upgrader output is in English
     Given a WP install
+    And I run `wp theme activate twentytwenty`
     And an empty cache
     And I run `wp core download --version=5.4.1 --force`