plugins/dap-go: require dap to be explicitly enabled

Instead of automatically enabling `plugins.dap`, require users to
explicitly enable it. This prevents silent re-enabling of dap when
a user has explicitly disabled it.

plugins/by-name/dap-go/default.nix

@@ -1,4 +1,5 @@
 {
+  config,
   lib,
   ...
 }:
@@ -12,12 +13,16 @@ lib.nixvim.plugins.mkNeovimPlugin {
   # Manually supplied to nvim-dap config module
   callSetup = false;
   extraConfig = cfg: {
-    plugins.dap = {
-      enable = true;
-      extensionConfigLua = ''
-        require("dap-go").setup(${lib.nixvim.toLuaObject cfg.settings})
+    assertions = lib.nixvim.mkAssertions "plugins.dap-go" {
+      assertion = config.plugins.dap.enable;
+      message = ''
+        You have to enable `plugins.dap` to use `plugins.dap-go`.
       '';
     };
+
+    plugins.dap.extensionConfigLua = ''
+      require("dap-go").setup(${lib.nixvim.toLuaObject cfg.settings})
+    '';
   };
   # NOTE: Renames added in https://github.com/nix-community/nixvim/pull/2897 (2025-01-26)
   imports = [ ./deprecations.nix ];