QAG-31: (fix) Add purger processors configuration for Varnish

- Add purge processors configuration to ensure proper cache invalidation
- Enable drush_purge_invalidate processor to allow manual invalidation via Drush
- Enable lateruntime processor for efficient batching of invalidations
- Enable purge_ui_block_processor for admin UI purging functionality

Refs: config/sync/purge.plugins.yml

Author: tormi

config/sync/purge.plugins.yml

@@ -3,3 +3,16 @@ purgers:
     instance_id: c6013ef2d0
     plugin_id: varnish
     order_index: 2
+processors:
+  -
+    plugin_id: drush_purge_queue_work
+    status: false
+  -
+    plugin_id: drush_purge_invalidate
+    status: true
+  -
+    plugin_id: lateruntime
+    status: true
+  -
+    plugin_id: purge_ui_block_processor
+    status: true