fix: clear the content layer cache when the Astro config changes

[ascorbic]

Changes

Currently the content layer cache is invalidated if the content config or Astro version changes. However this causes problems if there are changes in the Astro config that also affect the stored data. This can include things like markdown settings, but potentially lots of other things.

The apporach this PR takes is to hash everything except integrations, adapters and vite config. It switches the digest function to use a safe stringify function in case the Astro config includes circular refs.

Closes #12761

Testing

Adds a test case

Docs

[changeset-bot]

🦋 Changeset detected

Latest commit: 2c1cbc6

The changes in this PR will be included in the next version bump.

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[codspeed-hq]

CodSpeed Performance Report

Merging #12767 will not alter performance

_{Comparing clear-on-config-up (2c1cbc6) with main (8da2318)}

Summary

✅ 4 untouched benchmarks

[ascorbic]

Huh. They passed locally but now aren't.

[delucis]

Tests are failing but looks good to me in principle!

[ematipico]

I think we should change how we hash the config.

[delucis]

LGTM!

[delucis]

Ah, hang on. Seeing “Maximum call stack exceeded” in the object hasher in tests:

Node 18 only for some reason, but could still be problematic I guess.

[ascorbic]

Oh that isn't good! I'll look into it tomorrow

[ascorbic]

I'm going to switch back to the safe stringify approach because it looks like deterministic-object-hash doesn't have any circular dependency handling or any other handling of excessively deep objects. That's fine for simple things like the image transforms, but astro config can be complex.