Merge pull request #420 from cloudfoundry/renovate/helm-3.x

Update dependency helm to v3.18.4

Author: jochenehret

.tool-versions

@@ -1,6 +1,6 @@
 concourse 7.13.1
 gcloud 522.0.0
-helm 3.18.0
+helm 3.18.4
 kapp 0.64.2
 kubectl 1.33.1
 python 3.13.3