CI: Add node 24.x to ci and remove 21.x

[paladox]

24.x is a lts release. 21.x was just a normal release, never a lts so can be dropped.

[github-actions]

Build Size Report

Changes to minified artifacts in /build, after gzip compression.

1 file changed

Total change +1 B

View Changes

file	base	pr	diff
highlight.min.js	8.23 KB	8.23 KB	+1 B

[joshgoebel]

Both Node.js 18 and Node.js 20 have reached their official End-of-Life (EOL), meaning they are no longer supported by the Node.js Foundation and receive no further security patches.Node.js 18: Reached EOL on April 30, 2025.Node.js 20: Reached EOL on April 30, 2026.

I say lets lose 18 and 20 as well...

[arturict]

If this introduces CI matrix adjustments, a quick matrix summary in PR body helps triage runtime compatibility concerns.

[joshgoebel]

Thanks for this — dropping 21 and adding 24 LTS looks good.

Could you also add 26.x (current Current) so the matrix matches the comment about LTS + Current?

node-version: [18.x, 20.x, 22.x, 24.x, 26.x]

We'll drop 18 later with v12.

[joshgoebel]

Looks like 20 is still LTS, so no reason I can think of not to keep for now.