treewide: add missing systemd ordering directives

In particular, we were missing `sops-install-secrets.service` in a ton
of places, and `network-online.target` for some homebrewn services.

This has caused failure of some services on machine startup.

hosts/bicep/services/matrix/hookshot/default.nix

@@ -183,6 +183,7 @@ in
   };
 
   services.matrix-hookshot.serviceDependencies = [
+    "sops-install-secrets.service"
     "matrix-synapse.target"
     "nginx.service"
   ];