Update marketing buttons (including color mode support)

[tobiasahlin]

This PR upstreams the latest changes to marketing buttons from github.com, which includes proper support for color modes. Preview:

buttons-draft.mov

primer/primitives#265 is intended to land first (primer/primitives@7.0.1), at which point this PR can be updated to use those variables instead of local overrides.

/cc @primer/css-reviewers

[changeset-bot]

🦋 Changeset detected

Latest commit: 2a84afa

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

This PR includes changesets to release 1 package

Name	Type
@primer/css	Major

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[simurai]

So far looks good. ✨

Are the !important needed to override utilities?

[simurai]

Ok, did the following:

1. Updated primer/primitives to 7.0.1 that includes the new mktg variables e372b03
2. Replace the temp variables with primer/primitives variables e258ff5

@tobiasahlin does this 👀 preview look right? Looks good to me. 👍

Maybe one question before merging: When we ship this to dotcom, will there be lots of refactoring needed? Like replace all the updated btn classes?

[tobiasahlin]

@simurai amazing, thank you for pulling in those changes and replacing all the overrides! 🙏

Preview looks great 👀 I just replaced the replacement suggestion of btn-transparent → btn-muted-mktg with btn-transparent → btn-subtle-mktg

Maybe one question before merging: When we ship this to dotcom, will there be lots of refactoring needed? Like replace all the updated btn classes?

@simurai yes a few updates, but it'll be a fairly light lift. All of these styles are already in .com with custom overrides, so there'll be no visual changes with this update, just replacing classes and cleaning up the temporary custom overrides 🙏

[simurai]

Ok, let's 🚢 this.