Drop prefixer

[Andarist]

closes #2747

IMHO, this plugin is not really needed in 2025, but I haven't rechecked whether all the included rules are obsolete. Many are, we definitely shouldn't be prefixing flexbox

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🦋 Changeset detected

Latest commit: 37fa86e

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 8 packages

Name	Type
@emotion/styled	Major
@emotion/cache	Major
@emotion/react	Major
@emotion/css	Major
@emotion/primitives-core	Major
@emotion/server	Major
@emotion/native	Major
@emotion/primitives	Major

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[emmatown]

I basically agree with this (and probably agree with shipping it in the next major in a way that I don't really with #3294) with the caveat that to understand whether all of it is actually obselete, it'd be good to see something like: run the stylis prefixer over some specifically generated css to exercise all the properties that stylis prefixes, compare that with caniuse/mdn compat data/whatever and see what we get

[Andarist]

Quick look on caniuse:

declaration	browser support	notes
color-adjust	19%	deprecated
animation, animation-(delay|direction|duration|fill-mode|iteration-count|name|play-state|timing-function)	97%
text-decoration	83%	97% with prefixes
filter	98%
clip-path	95%
backface-visibility	97%
column	97%
box-decoration-break	69%	98% with prefixes
mask, mask-image, mask-(mode|clip|size), mask-(repeat|origin), mask-position, mask-composite,	92.5%	98% with prefixes
background-clip	97%
columns, column-(count|fill|gap|rule|rule-color|rule-style|rule-width|span|width)	97%
appearance	96%
user-select	79%	97% with prefixes
transform,	98%
hyphens	94%
text-size-adjust	77%	92% with prefixes
transition	97%
cursor	80%	no change with prefixes
background, background-image	97%
(margin|padding)-inline-(start|end)	97%
(min|max)?(width|height)	97%
(min|max)(inline-size|block-size)	96%
stretch, max-content, min-content, fill-available	97%
(m)ax-content, (m)in-content	97%
(f)ill-available, (f)it-content	97%
(s)tretch	98%
position: sticky	97%
writing-mode	98%
vertical-l(r)	97%
vertical-r(l)	97%
horizontal(-)tb	97%
:read-(only|write)	98%
:placeholder	97.7%

[Andarist]

🏓 @emmatown

[emmatown]

Sorry, I looked more into this before the holidays and got side-tracked, basically my thoughts are since the number of properties where prefixes are still relevant seems to be not nothing, I think we should probably have a smaller prefixer that includes what is currently prefixed but excluding everything that is Baseline "Widely Available" (I don't think the estimated browser support percentages to decide things is very useful). Over time, it would shrink, though the exact details of how we'd want to do that wrt to major versions, I'm not super sure about.