preload fonts by default

[benmccann]

Describe the problem

According to #4963, @Rich-Harris said we don't preload fonts by default because they may be imported but not used on a page. Though I'm not sure that's a great reason for us to not do it by default as that seems like the user has coded things incorrectly in that case

Describe the proposed solution

Maybe Vite could issue a warning for fonts that are imported, but never used if we really care about detecting that

Alternatives considered

No response

Importance

nice to have

Additional Information

Font preloading sometimes doesn't work before Vite 5. Fixed in vitejs/vite#14297

[dummdidumm]

We removed loading fonts by default in #7704 because there were too many false positives. Fonts in general can be very dynamic (fallback fonts, load a different font based on a unicode range) and as such just loading them upfront when detected anywhere on the page was turning out to be the wrong default. I'm against switching this, unless we can somehow find out which fonts are definitely loaded.

[benmccann]

Hmm. I'd be curious if we can get some data around this. I'll close this for now I guess

[dummdidumm]

Reopening so we can continue at some point to look into this, but taking this off the 2.0 milestone