Add Nextcloud deployment and configuration

- Introduced Nextcloud module with Kubernetes resources including deployment, service, ingress, and cron job.
- Configured Apache settings for Nextcloud with SSL support and compression.
- Created secrets for mail and admin credentials.
- Added necessary environment variables for Nextcloud configuration.
- Removed unused Scaleway access and secret keys from secrets and variables.
- Updated CoreDNS module to support custom host overrides.
- Implemented backup bucket policies and lifecycle rules for Scaleway object storage.
- Enhanced IAM policies and applications for backup and email services.
- Added outputs for backup bucket and API keys.

terraform/modules/apps/nextcloud/provider.tf

@@ -0,0 +1,9 @@
+terraform {
+  required_version = "~>1.8"
+  required_providers {
+    kubernetes = {
+      source  = "hashicorp/kubernetes"
+      version = "2.36.0"
+    }
+  }
+}