Premium analytics: remove token fallbacks

[simison]

Follow-up to #50502, which removed token fallbacks for routes.

This removes fallbacks from components used within premium analytics route, but that aren't under routes folder directly.

No big difference in output bundles; the fallbacks were previously added manually, now they're just added as part of the build process:

8 incorrect manual fallback values removed — since wpds var was used already, these should not have actual affect on UI:

Token	Before (removed)	After
--wpds-border-radius-md	8px	4px
--wpds-border-width-focus	1.5px	var(--wp-admin-border-width-focus, 2px)
--wpds-color-foreground-content-neutral-weak	#646970, #757575, currentColor	#707070
--wpds-color-stroke-surface-neutral-weak	#e0e0e0	#f0f0f0 (theme)
--wpds-dimension-gap-md	16px	12px
--wpds-typography-font-weight-medium	500	499

Proposed changes

• Remove token fallbacks from Premium Analytics folder; they're added at build time so there's no need to manually manage them, which is more work and risks incorrect ones.
• Adds entire folder to linter "no fallbacks" linter.
• Skips icons package (projects/packages/premium-analytics/packages/icons/*); linter ignores them, and they'd need a different solution.

Related product discussion/links

Does this pull request change what data or activity we track or use?

Testing instructions

• Smoke test premium analytics; no visual regressions.

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Premium Analytics plugin:

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Code Coverage Summary

This PR did not change code coverage!

That could be good or bad, depending on the situation. Everything covered before, and still is? Great! Nothing was covered before? Not so great. 🤷

Full summary · PHP report

[retrofox]

LGTM. I've tested the branch and didn't find any visual changes. Let's keep checking in on follow-ups and tweak it if needed 🚀

Thanks, Mikael 🙇‍♂️