[DRAFT] getCollection perf improvements when called multiple times

[bholmesdev]

What kind of changes does this PR include?

• Changes to the docs site code

Description

@delucis Found that calling getCollection('docs') in multiple places noticeably slowed builds over centralizing to a since getCollection() call. This branch experiments with a caching layer in core for prod builds to get the same benefits.

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[delucis]

Ooh, very interesting! Looks like it’s working right?

Funnily enough, I’ve actually really enjoyed the import { pages } from '~/content' pattern we were pushed into, but happy to see we might be able to help ensure that performance for everyone, without them needing to hunt for that optimisation. Thanks Ben 💜

[bholmesdev]

@delucis totally! I don't plan to merge this PR, just using it to test build times in CI. Seems to replicate the ~10% reduction in build times I've been seeing locally 😄

Also happy to report there's no noticeable increase in memory usage when adding this cache. Feeling confident we can open a core PR for this. Thanks for exploring this during the migration so we could improve!