Upgrade mariadb Helm chart to 8.0.0 (#48)

Upgrade mariadb Helm chart to 8.0.0

The names of the values changed in the new Helm chart, see [1]. Thus the
Helm chart ships breaking changes and therefore bump the major version
of this Chart.yaml (not sure if you use semver?)

Furthermore, there is a bug [2] where not setting the root password
results in the mariadb entering a CrashLoopBackOff when re-installing
it. Thus set it (as done in the mysql values already).

[1] 1206942b69
[2] https://github.com/bitnami/charts/issues/3884

Co-authored-by: Andre Schröder <andre.schroedr@gmail.com>
Reviewed-on: https://gitea.com/gitea/helm-chart/pulls/48
Reviewed-by: Andrew Thornton <art27@cantab.net>
Reviewed-by: luhahn <luhahn@noreply.gitea.io>
Co-Authored-By: schra <schra@noreply.gitea.io>
Co-Committed-By: schra <schra@noreply.gitea.io>

Chart.yaml

@@ -2,7 +2,7 @@ apiVersion: v2
 name: gitea
 description: Gitea Helm chart for Kubernetes
 type: application
-version: 1.5.5
+version: 2.0.0
 appVersion: 1.12.5
 icon: https://docs.gitea.io/images/gitea.png
 
@@ -41,5 +41,5 @@ dependencies:
   condition: gitea.database.builtIn.postgresql.enabled
 - name: mariadb
   repository: https://charts.bitnami.com/bitnami
-  version: 7.10.2
+  version: 8.0.0
   condition: gitea.database.builtIn.mariadb.enabled