feat: gitea runner cache config

hosts/fw/modules/gitea-vm.nix

@@ -62,6 +62,11 @@ in {
           container = {
             network = "podman";
           };
+          cache = {
+            enabled = true;
+            host = "${config.networkPrefix}.97.5${toString idx}";  # LAN IP of the machine running act_runner
+            port = 8088;                                           # any free TCP port
+          };
         };
       };