Harden check-update test (#520)

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Author: swissspidy

features/plugin-check-update.feature

@@ -4,7 +4,9 @@ Feature: Check for plugin updates
   Scenario: Check for plugin updates with no updates available
     Given a WP install
 
-    When I run `wp plugin install wordpress-importer --activate`
+    # In case Akismet has a newer release than the bundled version
+    When I run `wp plugin update --all`
+    And I run `wp plugin install wordpress-importer --activate`
     Then STDOUT should not be empty
 
     When I run `wp plugin check-update --all`