Fix docs and demo build scripts

[AlbertBrand]

Fixes deployment issues (I hope)

[netlify]

❌ Deploy Preview for slidev failed.

Name	Link
🔨 Latest commit	7828387
🔍 Latest deploy log	https://app.netlify.com/projects/slidev/deploys/69394dac46ef31000801d0cc

[pkg-pr-new]

Open in StackBlitz

@slidev/client

npm i https://pkg.pr.new/slidevjs/slidev/@slidev/client@2403

create-slidev

npm i https://pkg.pr.new/slidevjs/slidev/create-slidev@2403

create-slidev-theme

npm i https://pkg.pr.new/slidevjs/slidev/create-slidev-theme@2403

@slidev/parser

npm i https://pkg.pr.new/slidevjs/slidev/@slidev/parser@2403

@slidev/cli

npm i https://pkg.pr.new/slidevjs/slidev/@slidev/cli@2403

@slidev/types

npm i https://pkg.pr.new/slidevjs/slidev/@slidev/types@2403

commit: 7828387

[AlbertBrand]

@antfu @kermanx strange, this change works locally. Is netlify reusing runners? It might be some leftover files issue.