Drop eln from RHEL 8 ACG Level 1

ACG Level 1 packages provide stability for a very select subset of packages
until RHEL N+2.  Now that ELN targets the future RHEL 11, compatibility with
RHEL 8 is no longer required.

Author: yselkowitz

configs/rhel-sst-program--acg-level1-el8.yaml

@@ -24,5 +24,4 @@ data:
     - vulkan-loader
     - zlib-ng-compat
   labels:
-    - eln
     - c10s