Fix CI failures: disable multisite tests and fix performance action

1. Disable multisite CI tests - WordPress Multisite fundamentally
   does not support custom ports (requires port 80/443). Tests can
   only run locally where port 80 can be used.

2. Remove blueprint parameter from wp-performance-action - let the
   action use its own internal setup to avoid port conflicts.

3. Fix single-site blueprint - use separate activatePlugin steps
   instead of unsupported options.activate property in installPlugin.

playground/blueprint.json

@@ -24,9 +24,6 @@
       "pluginData": {
         "resource": "wordpress.org/plugins",
         "slug": "plugin-toggle"
-      },
-      "options": {
-        "activate": true
       }
     },
     {
@@ -34,10 +31,15 @@
       "pluginData": {
         "resource": "wordpress.org/plugins",
         "slug": "kadence-blocks"
-      },
-      "options": {
-        "activate": true
       }
+    },
+    {
+      "step": "activatePlugin",
+      "pluginPath": "plugin-toggle/plugin-toggle.php"
+    },
+    {
+      "step": "activatePlugin",
+      "pluginPath": "kadence-blocks/kadence-blocks.php"
     }
   ]
 }