Emit theme colors as CSS vars with fallbacks; add webCompatibility SVG normalize - #8008

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea, release-drafter/release-drafter@267d2e0268deae5d44f3ba5029dd4d6e85f9d52d. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

"pull_request_target.edited" is not a known webhook name (https://developer.github.com/v3/activity/events/types/)

"pull_request_target.synchronize" is not a known webhook name (https://developer.github.com/v3/activity/events/types/)

"pull_request_target.reopened" is not a known webhook name (https://developer.github.com/v3/activity/events/types/)