[doc & comment conflict] document and comments about build.target are a little confused

[zhaojjiang]

Describe the bug

about build.target

The document shows

https://vite.dev/guide/build.html#browser-compatibility

Note that by default, Vite only handles syntax transforms and does not cover polyfills.

But the code comment shows except for dynamic import

vite/packages/vite/src/node/build.ts

Lines 81 to 83 in ac32968

	* and the lowest supported target is es2015/es6. Note this only handles
	* syntax transformation and does not cover polyfills (except for dynamic
	* import)

A few days ago, we found dynamic-imports compatibility error, so I tried to found more info about the difference bwtween build.target and @vitejs/plugin-legacy, and then found there are some conflict description.

The comment was added since 4 years ago, maybe it is outdated?

Reproduction

document & code comment

Steps to reproduce

No response

System Info

system independent

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.

[sapphi-red]

Yeah, the code comment is outdated.