fix fs-read-empty-buffer.test.js

[nektro]

No description provided.

[robobun]

❌ @nektro, your commit 5ab3d04 has 8 failures in #4313:

test/js/web/fetch/fetch-tcp-stress.test.ts - timeout on 🍎 13 x64

test/js/web/fetch/fetch-tcp-stress.test.ts - timeout on 🍎 14 x64

test/js/node/test/parallel/fs-watch-recursive-watch-file.test.js - timeout on 🐧 20.04 aarch64

test/cli/run/run-crash-handler.test.ts - timeout on 🪟 x64

test/cli/run/run-crash-handler.test.ts - timeout on 🪟 x64-baseline

test/cli/hot/hot.test.ts - 1 failing on 🪟 x64-baseline

test/cli/hot/watch.test.ts - 1 failing on 🪟 x64

test/cli/hot/watch.test.ts - 1 failing on 🪟 x64-baseline

test/cli/watch/watch.test.ts - 2 failing on 🪟 x64

test/cli/watch/watch.test.ts - 2 failing on 🪟 x64-baseline

test/js/bun/http/fetch-file-upload.test.ts - 1 failing on 🪟 x64

test/js/bun/http/bun-serve-static.test.ts - 2 failing on 🍎 13 aarch64