vite can't pack svg into css, but png can

[peakDragonCheung]

Describe the bug

Reproduction

https://stackblitz.com/edit/vitejs-vite-zqzyhk?file=src/App.svelte

System Info

System:
    OS: Windows 10 10.0.19043
    CPU: (12) x64 Intel(R) Core(TM) i5-10500 CPU @ 3.10GHz
    Memory: 11.30 GB / 31.72 GB
  Binaries:
    Node: 16.13.1 - C:\Program Files\nodejs\node.EXE
    Yarn: 1.22.17 - C:\Program Files\nodejs\yarn.CMD
    npm: 8.1.2 - C:\Program Files\nodejs\npm.CMD
  Browsers:
    Edge: Spartan (44.19041.1266.0), Chromium (99.0.1150.36)
    Internet Explorer: 11.0.19041.1202
  npmPackages:
    vite: ^2.8.0 => 2.8.6

Used Package Manager

npm

Logs

vite v2.8.6 building for production...
✓ 9 modules transformed.
dist/assets/file_bg.f8fde818.svg   1.09 KiB
dist/index.html                    0.50 KiB
dist/assets/index.f4f850ce.js      2.15 KiB / gzip: 1.13 KiB
dist/assets/vendor.be9a72b0.js     3.15 KiB / gzip: 1.45 KiB
dist/assets/index.cf80e917.css     0.85 KiB / gzip: 0.45 KiB

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to https://github.com/vuejs/core instead.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[sapphi-red]

I think this is duplicate of #1204.