refactor!: remove Seafile

I don't use Seafile that much, and the new version is kind of a pain
to set up (CSRF failed, hard to configure automatically, etc.).

I haven't chosen an alternative yet, but it may come in the future.

apps/seafile/Chart.yaml

@@ -1,7 +0,0 @@
-apiVersion: v2
-name: seafile
-version: 0.0.0
-dependencies:
-  - name: seafile
-    version: 2.0.1
-    repository: https://k8s-at-home.com/charts

apps/seafile/values.yaml

@@ -1,18 +0,0 @@
-seafile:
-  ingress:
-    main:
-      enabled: true
-      ingressClassName: nginx
-      annotations:
-        cert-manager.io/cluster-issuer: letsencrypt-prod
-      hosts:
-        - host: &host seafile.khuedoan.com
-          paths:
-            - path: /
-              pathType: Prefix
-      tls:
-        - secretName: seafile-tls-certificate
-          hosts:
-            - *host
-  mariadb:
-    enabled: true