Run setup commands in a single process in tests (#351)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

Author: schlessera

features/core-update-db.feature

@@ -205,8 +205,10 @@ Feature: Update core's database
     And I run `wp site create --slug=net2-site2 --porcelain`
     And save STDOUT as {NET2_SITE2_ID}
     # Register a second network (ID=2) and reassign those two blogs to it
-    And I run `wp eval 'global $wpdb; $wpdb->insert( $wpdb->site, [ "domain" => "example.com", "path" => "/network2/" ] );'`
-    And I run `wp eval 'global $wpdb; $wpdb->update( $wpdb->blogs, [ "site_id" => 2 ], [ "blog_id" => {NET2_SITE1_ID} ] ); $wpdb->update( $wpdb->blogs, [ "site_id" => 2 ], [ "blog_id" => {NET2_SITE2_ID} ] );'`
+    And these setup commands:
+      | command                                                                                                                                                                                           |
+      | wp eval 'global $wpdb; $wpdb->insert( $wpdb->site, [ "domain" => "example.com", "path" => "/network2/" ] );'                                                                                      |
+      | wp eval 'global $wpdb; $wpdb->update( $wpdb->blogs, [ "site_id" => 2 ], [ "blog_id" => {NET2_SITE1_ID} ] ); $wpdb->update( $wpdb->blogs, [ "site_id" => 2 ], [ "blog_id" => {NET2_SITE2_ID} ] );' |
 
     When I run `wp site option get wpmu_upgrade_site`
     Then save STDOUT as {UPDATE_VERSION}