Complete fix: delete resource records when deleting resource pool

This completes the fix from PR #2315 by ensuring that when a resource
pool is deleted, all associated resource records are also deleted from
the resources table, preventing orphaned resource records.

Changes:
- Modified delete_resource_pool() to first delete all resource records
  in the pool before deleting the pool itself
- This complements the existing fix in remove_resource_from_pool() which
  handles single resource removal

gns3server/db/repositories/pools.py

@@ -156,6 +156,14 @@ class ResourcePoolsRepository(BaseRepository):
         Delete a resource pool.
         """
 
+        # Get all resources in the pool first
+        resources = await self.get_pool_resources(resource_pool_id)
+
+        # Delete all resource records
+        for resource in resources:
+            await self.delete_resource(resource.resource_id)
+
+        # Now delete the resource pool
         query = delete(models.ResourcePool).where(models.ResourcePool.resource_pool_id == resource_pool_id)
         result = await self._db_session.execute(query)
         await self._db_session.commit()