Auto map optimizePackageImports to transpilePackages for pages (#63537)
This ensures `optimizePackageImports` doesn't unexpectedly fail to apply
for `pages` as they aren't transpiled/bundled by default without either
`transpilePackages` being used or `experimental.bundlePagesExternals`.
This also ensures our docs correctly show this config in the pages docs
as currently in only shows in `app`.
x-ref: [slack
thread](https://vercel.slack.com/archives/C0676QZBWKS/p1710967294942029)
Closes NEXT-2884