Update jenkins/ath Docker tag to v5581 (jenkinsci#7973)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

ath.sh

@@ -6,7 +6,7 @@ set -o xtrace
 cd "$(dirname "$0")"
 
 # https://github.com/jenkinsci/acceptance-test-harness/releases
-export ATH_VERSION=5568.v2b_9ea_7d7ea_98
+export ATH_VERSION=5581.vfd8e43f46a_03
 
 if [[ $# -eq 0 ]]; then
 	export JDK=11