chore(deps): update helm release postgresql to v18

Author: renovate[bot]

charts/calcom-stack/Chart.yaml

@@ -7,7 +7,7 @@ appVersion: v5.0.19
 dependencies:
   - name: postgresql
     repository: https://charts.bitnami.com/bitnami
-    version: 16.6.6
+    version: 18.2.6
   - name: calcom
     repository: https://pyrrha.github.io/calcom-helm
     version: 0.8.6