Isr - revalidation for stale data

[DarrenBaldwin07]

• Enables Incremental static regeneration on 10 second intervals
• Nextjs will now try to regenerate static data after 10 seconds after the first request - if the page generation fails, it will fallback to the old data and try again later
• The main benefit of adding this is that pgt.dev will now not need site re-builds for when extensions and extension meta data changes. We also do not lose any SEO + perf benefits of SSG because HTML is still being generated at build time (its just being regenerated when data is potentially stale)
• This PR also removes the /api/regenerate route because it was not working in production due to Amplify not supporting on-demand revalidation

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[ianstanton]

Looks good! 🎉 Looks like CI wants us to bump the CLI crate because we modified its .gitignore. We can either bump that or tweak the CI to ignore changes to this file.