Bug Description

When using code optimization to drop unused code, assets that were emitted but no longer referenced are still emitted.

Link to Minimal Reproduction and step to reproduce

https://github.com/MattIPv4/webpack-asset-repro

• npm ci
• npm run build
• ls dist/*.png
• for each file.png, cat dist/main.js | grep <file.png>

One png should be referenced in dist/main.js, while the other won't be as it was used by dead code.

Expected Behavior

Assets that are emitted but later made unused by code optimization should be removed from the emitted assets

Actual Behavior

Assets are always emitted even if all references to them are dropped by code optimization

Environment

System:
    OS: macOS 26.1
    CPU: (14) arm64 Apple M4 Pro
    Memory: 97.52 MB / 24.00 GB
  Binaries:
    Node: 22.13.1 - /Users/mattcowley/.local/state/fnm_multishells/85154_1765079840717/bin/node
    npm: 10.9.2 - /Users/mattcowley/.local/state/fnm_multishells/85154_1765079840717/bin/npm
    pnpm: 10.20.0 - /Users/mattcowley/.local/state/fnm_multishells/85154_1765079840717/bin/pnpm
  Browsers:
    Chrome: 142.0.7444.177
    Firefox Developer Edition: 146.0
    Safari: 26.1
    Safari Technology Preview: 26.0
  Packages:
    webpack-cli: ^6.0.1 => 6.0.1

Is this a regression?

None

Last Working Version

No response

Additional Context

No response