build: upgrade chroma-js to 2.4.2

[tkajtoch]

Summary

This PR resolves Snyk dependency upgrade recommendation from #6799 by upgrading chroma-js and @types/chroma-js to their latest versions.

chroma-js changelog diff

• add support for Oklab and Oklch color spaces
• use binom of degree n in chroma.bezier
• use Delta e2000 for chroma.deltaE Delta e2000 gka/chroma.js#269

QA

• (chroma.mix) Open <EuiBottomBar /> component docs, open the bottom bar and make sure the background color is rgb(19, 19, 23)

• (chroma.hsv) Ensure <EuiColorPicker /> HSV color selection in prod and PR environment results in the same colors.

• (chroma.scale) Open <EuiColorPicker />, scroll down to Stepped color segments and ensure the background CSS property value for its euiRangeHighlightProgress test subject is:

  See value

  linear-gradient(to right, transparent 19%, rgb(84, 179, 153) 19%, rgb(84, 179, 153) 23.28%, rgb(105, 165, 150) 23.28%, rgb(105, 165, 150) 27.56%, rgb(126, 151, 147) 27.56%, rgb(126, 151, 147) 31.84%, rgb(148, 138, 144) 31.84%, rgb(148, 138, 144) 36.12%, rgb(169, 124, 140) 36.12%, rgb(169, 124, 140) 40.4%, rgb(190, 110, 137) 40.4%, rgb(190, 110, 137) 44.68%, rgb(211, 96, 134) 44.68%, rgb(211, 96, 134) 48.96%, rgb(189, 101, 151) 48.96%, rgb(189, 101, 151) 53.24%, rgb(167, 107, 167) 53.24%, rgb(167, 107, 167) 57.52%, rgb(145, 112, 184) 57.52%, rgb(145, 112, 184) 61.8%)

General checklist

• Checked in Chrome, Safari, Edge, and Firefox

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_7039/

[kibanamachine]

Preview documentation changes for this PR: https://eui.elastic.co/pr_7039_buildkite/

[elasticmachine]

💚 Build Succeeded

• Buildkite Build
• Commit: da32c99

cc @tkajtoch

[1Copenut]

👍 LGTM! I retested your QA steps in Chrome on the Buildkite preview. All colors matched exactly.