chore(deps): update mariadb docker tag to v20 (#402)

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

This major bump updates the MariaDB subchart to version 20.0.0. This subchart updates the StatefulSet objects `serviceName` to use a headless service, as the current non-headless service attached to it was not providing DNS entries. This will cause an upgrade issue because it changes "immutable fields". To workaround, it, delete the StatefulSet objects as follows (replace the RELEASE_NAME placeholder):

```shell
kubectl delete sts RELEASE_NAME-mariadb --cascade=false
```

Then execute `helm upgrade` as usual.

charts/yourls/Chart.yaml

@@ -1,5 +1,5 @@
 apiVersion: v2
-version: 6.1.14
+version: 7.0.0
 name: yourls
 description: Your Own URL Shortener
 # renovate: image=ghcr.io/yourls/yourls
@@ -27,7 +27,7 @@ dependencies:
     tags:
       - bitnami-common
   - name: mariadb
-    version: ^19.1.2
+    version: ^20.0.0
     repository: oci://registry-1.docker.io/bitnamicharts
     condition: mariadb.enabled
     tags: