add vault secret of gitea backups

vault/kubernetes-roles/backup.yaml

@@ -0,0 +1,6 @@
+bound_service_account_names:
+  - backup
+bound_service_account_namespaces:
+  - gitea
+token_policies:
+  - backup

vault/policy/backup.hcl

@@ -0,0 +1,7 @@
+path "secret/data/restic" {
+    capabilities = ["read"]
+}
+
+path "secret/data/backblaze" {
+    capabilities = ["read"]
+}