chore(deps): update helm release mariadb to v20

Author: renovate[bot]

charts/librenms/Chart.yaml

@@ -36,7 +36,7 @@ sources:
 
 dependencies:
   - name: mariadb
-    version: ~18.2.0
+    version: ~20.4.0
     repository: https://charts.bitnami.com/bitnami
     condition: mariadb.enabled
   - name: redis