tools/generic_s3: remove unused condition

This is a copypaste from other tests. Test can be ran on nightlies and
is passing.

tools/generic_s3_test.sh

@@ -19,17 +19,6 @@ if [ -n "${CERTS_DIR}" ]; then
     fi
 fi
 
-if [ "${NIGHTLY:=false}" == "true" ]; then
-    case "${ID}-${VERSION_ID}" in
-        "rhel-8.6" | "rhel-9.0")
-            echo "$0 is not enabled for ${ID}-${VERSION_ID} skipping..."
-            exit 0
-            ;;
-        *)
-            ;;
-    esac
-fi
-
 set -euo pipefail
 
 # Container images for MinIO Server