packaging: script: Use rockylinux prefix on package testing script

Signed-off-by: Hiroshi Hatake <hiroshi@chronosphere.io>

Author: cosmo0920

packaging/test-release-packages.sh

@@ -51,9 +51,9 @@ YUM_TARGETS=(
     "almalinux:8"
     "almalinux:9"
     "almalinux:10"
-    "rockylinux:8"
-    "rockylinux:9"
-    "rockylinux:10"
+    "rockylinux/rockylinux:8"
+    "rockylinux/rockylinux:9"
+    "rockylinux/rockylinux:10"
     "quay.io/centos/centos:stream9"
     "quay.io/centos/centos:stream10"
     "amazonlinux:2"