Address code review feedback: improve nextTick polyfill and remove redundant dep

Co-authored-by: moufmouf <1290952+moufmouf@users.noreply.github.com>

Author: Copilot

test/setup-browser.ts

@@ -10,6 +10,6 @@ import { Buffer } from 'buffer'
 // Ensure process.nextTick is available
 if (!process.nextTick) {
   process.nextTick = function(fn: Function, ...args: any[]) {
-    Promise.resolve().then(() => fn(...args))
+    return Promise.resolve().then(() => fn(...args))
   }
 }

vitest.browser.config.ts

@@ -17,7 +17,7 @@ export default defineConfig({
     }
   },
   optimizeDeps: {
-    include: ['events', 'buffer', 'stream-browserify', 'util', 'process', 'process/browser']
+    include: ['events', 'buffer', 'stream-browserify', 'util', 'process/browser']
   },
   test: {
     globals: true,