fix(css): use esbuild legalComments config when minifying CSS

[niksy]

Description

If you set esbuild configuration with additional transform options, those options are passed down to JS minification process, but they’re ignored for CSS minification, resulting in situations where you can e.g. set legalComments option to different value and expect that it will be applied to both JS and CSS files, but it’s applied only to JS files.

Additional context

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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[bluwy]

A bit concerned with passing everything since the esbuild options is shared between JS too. Configuration like target might inadvertently override build.cssTarget. Is legalComments the only property you need here? We can pass that specifically here instead.

[niksy]

Yeah, I understand, that was also my concern. Currently it’s only legalComments, but the idea was to align this with JS options. Is there a list of explicit config fields such as build.cssTarget? Maybe we can omit them here to avoid conflicts.

[bluwy]

I think it's still better to opt-in properties individually like legalComments to be safe. e.g. banner and footer wouldn't really work in both CSS and JS too (arguably it's an edge cases). If there's more properties needed to pass, we can revisit passing the entire thing again if needed.

[niksy]

legalComments and lineLimit are options that could be applied to JS and CSS files in minification process. banner and footer could be adjusted to replace JS inline comments to block comments but I think that’s out of scope for this PR.

I’ve added only legalComments support, but let me know if it’s okay to work on other options.

[bluwy]

We can do legalComments for now and see if there's request for lineLimit in the future. IIRC it's a recent feature and isn't too bad for CSS if it's not used.

[bluwy]

Thanks!