fix(theme-classic): minor code copy button improvements - #6986

✅ [V2]

Name	Link
🔨 Latest commit	96457d3
🔍 Latest deploy log	https://app.netlify.com/sites/docusaurus-2/deploys/623c8d1e20eee00008e35048
😎 Deploy Preview	https://deploy-preview-6986--docusaurus-2.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

To edit notification comments on pull requests, go to your Netlify site settings.

✅ [V2]

Name	Link
🔨 Latest commit	96457d3
🔍 Latest deploy log	https://app.netlify.com/sites/docusaurus-2/deploys/623c8d3a3a0bea00086c0198
😎 Deploy Preview	https://deploy-preview-6986--docusaurus-2.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

To edit notification comments on pull requests, go to your Netlify site settings.

Ugh, the GitHub actions never kicked 😄

⚡️ Lighthouse report for the changes in this PR:

Lighthouse ran on https://deploy-preview-6986--docusaurus-2.netlify.app/

Size Change: 0 B

Total Size: 806 kB

_{compressed-size-action}

👍

I also think that the button is only ever reset to the original state after the timeout, so even when the cursor leaves the code block, the button stays as a tick, which seems a little weird. But changing that requires moving state management up to CodeBlock which seems too much trouble.

Note that technically we already have CopyButton CSS targeting a parent (but stable global) CSS selector so we could do the same with JS and attach a mouseOut listener

Not sure it's worth it though so I'll merge this as is