Merge branch 'renovate/promtail-3.x' into 'master'

Update Helm release promtail to v3.8.1

See merge request openappstack/openappstack!525

flux2/apps/monitoring/promtail-release.yaml

@@ -11,7 +11,7 @@ spec:
       # https://artifacthub.io/packages/helm/grafana/promtail
       # renovate: registryUrl=https://grafana.github.io/helm-charts
       chart: promtail
-      version: 3.6.0
+      version: 3.8.1
       sourceRef:
         kind: HelmRepository
         name: grafana