[Bug]: Rspack cssParser will parse failed when url(' ')

[GiveMe-A-Name]

System Info

System:
OS: macOS 13.6.5
CPU: (10) arm64 Apple M1 Pro
Memory: 87.03 MB / 32.00 GB
Shell: 5.9 - /bin/zsh
Binaries:
Yarn: 1.22.19 - /opt/homebrew/bin/yarn
npm: 10.9.0 - ~/Library/Application Support/fnm/node-versions/v22.12.0/installation/bin/npm
pnpm: 9.15.0 - ~/Library/pnpm/pnpm
bun: 1.0.21 - ~/.bun/bin/bun
Browsers:
Chrome: 131.0.6778.205
Safari: 16.6
npmPackages:
@rspack/cli: ^1.1.8 => 1.1.8
@rspack/core: ^1.1.8 => 1.1.8
@rspack/plugin-react-refresh: 1.0.0 => 1.0.0

Details

If i write url(' ') in css file.

.red {
  fg: green url('    ');
}

In webpack, it can compile success, but compile failed in rspack.

ERROR in ./src/style.css
  × Empty dependency: Expected a non-empty request
   ╭─[2:16]
 1 │ .red {
 2 │   fg: green url('    ');
   ·                 ──────
 3 │ }
   ╰────

The webpack will ignore the url if it;s

Reproduce link

https://github.com/GiveMe-A-Name/rspack-css-parser-test

Reproduce Steps

1. pnpm install
2. npm run start
3. npm run start:webpack