Legacy script is injected with an incorrect relative path in the built HTML file when using @vitejs/plugin-legacy:5.4.2

[gyutaesi]

Describe the bug

When using the @vitejs/plugin-legacy plugin with Vite, the polyfill script is injected into the built index.html file with an incorrect path.
Even after setting the base option, the path for the polyfills-legacy script lacks an absolute path (e.g., /assets/), causing the browser to throw an error, as it cannot locate the polyfill file.

The above issue does not occur in version 5.4.1, but only in version 5.4.2

Reproduction

none

Steps to reproduce

Run npm install & npm run build

System Info

System:
    OS: macOS 14.6.1
    CPU: (12) arm64 Apple M3 Pro
    Memory: 121.41 MB / 36.00 GB
    Shell: 5.9 - /bin/zsh
  Binaries:
    Node: 21.7.1 - ~/.nvm/versions/node/v21.7.1/bin/node
    Yarn: 1.22.22 - ~/.nvm/versions/node/v21.7.1/bin/yarn
    npm: 10.5.0 - ~/.nvm/versions/node/v21.7.1/bin/npm
    pnpm: 9.6.0 - ~/.nvm/versions/node/v21.7.1/bin/pnpm
  Browsers:
    Edge: 125.0.2535.92
    Safari: 17.6

Used Package Manager

npm

Logs

No response

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 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.

[github-actions]

Hello @gyutaesi. Please provide a minimal reproduction using a GitHub repository or StackBlitz. Issues marked with needs reproduction will be closed if they have no activity within 3 days.