🐛 Use denops-test as a default plugin name

Because Denops v7 restrict a plugin name.

vim-denops/denops.vim@fa4d678

Author: lambdalisue

tester_test.ts

@@ -88,7 +88,7 @@ test({
   fn: (denops) => {
     assertEquals(
       denops.name,
-      "@denops-test",
+      "denops-test",
     );
   },
 });

with.ts

@@ -7,7 +7,7 @@ import { run, type RunMode } from "./runner.ts";
 import { DenopsImpl } from "./denops.ts";
 import { errorDeserializer, errorSerializer } from "./error.ts";
 
-const PLUGIN_NAME = "@denops-test";
+const PLUGIN_NAME = "denops-test";
 
 // Timeout for connecting to Vim/Neovim
 // It takes a long time to start Vim/Neovim on Windows, so set a long timeout