[gitea] Moves database password into an sops secret

flake.nix

@@ -25,6 +25,10 @@
       url = "github:LnL7/nix-darwin/master";
       inputs.nixpkgs.follows = "nixpkgs";
     };
+    sops-nix = {
+      url = "github:Mic92/sops-nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
   };
 
   outputs = { self, nixpkgs, ... }@inputs: {