Ensure before-hydration is only loaded when used

[matthewp]

Changes

• Previously we were always loading an empty data: script in prod when before-hydration was unused, which is most apps. This required special CSP rules to allow importing data urls.
• Change is to only load that when it's actually needed by returning an empty string instead and not adding the attribute. Without the attribute the client will not attempt to load it.
• Fixes Unnecessary data script execution requires unsafe CSP #4762

Testing

• Test added for every scenario, SSG with and without the use of before-hydration, SSR before and without.

Docs

N/A, bug fix

[changeset-bot]

🦋 Changeset detected

Latest commit: 5adc2b7

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

This PR includes changesets to release 16 packages

Name	Type
astro	Patch
@e2e/astro-component	Patch
@e2e/error-cyclic	Patch
@e2e/error-react-spectrum	Patch
@e2e/error-sass	Patch
@e2e/errors	Patch
@e2e/hydration-race	Patch
@e2e/lit-component	Patch
@e2e/preact-component	Patch
@e2e/react-component	Patch
@e2e/solid-component	Patch
@e2e/solid-recurse	Patch
@e2e/svelte-component	Patch
@e2e/e2e-tailwindcss	Patch
@e2e/ts-resolution	Patch
@e2e/third-party-astro	Patch

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[tony-sull]

Nice! Great to see that extra data: script ripped out when it isn't used