don't try to treeshake test suite

Rollup was actually dropping a side-effect that was intentionally part of a test.

Author: ef4

vite.config.mjs

@@ -22,6 +22,7 @@ export default defineConfig(({ mode }) => {
   const build = {
     rollupOptions: {
       preserveEntrySignatures: 'strict',
+      treeshake: false,
       output: {
         preserveModules: true,
       },