chore: remove unused token

[wackerow]

Description

• Token accent-a-low-constrast was added in development of the ValuesMarquee component, but was ultimately not used. PR removes all traces
• Removed TODO about color clash: primary-action/primary-action-hover applied specifically to solid buttons and should not clash with text link primary, primary-hover, and primary-visited

Related Issue

Ongoing theming cleanup

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