Bump EPEL versions to fix nvidia build

Need a newer version of dkms than is available in the current snapshots:
```
 ==> openstack.openhpc:  Problem 1: cannot install the best candidate for the job
==> openstack.openhpc:   - nothing provides dkms >= 3.1.8 needed by kmod-nvidia-open-dkms-3:575.57.08-1.el9.noarch from cuda-rhel9-x86_64
```

Author: jovial

environments/common/inventory/group_vars/all/timestamps.yml

@@ -39,10 +39,10 @@ appliances_pulp_repos:
   epel:
     '8':
       path: epel/8/Everything/x86_64
-      timestamp: 20250326T000103
+      timestamp: 20250609T145306
     '9':
       path: epel/9/Everything/x86_64
-      timestamp: 20250326T000103
+      timestamp: 20250609T145306
   extras:
     '8.10':
       path: rocky/8.10/extras/x86_64/os