Deprecate Oxygen.env in favor of Hydrogen.env

[blittle]

Description

Oxygen.env is now deprecated in favor of Hydrogen.env. Access environment variables within your server components on Hydrogen.env. We hope this will make more sense when deploying to non-Oxygen environments.

Additional context

Part of https://github.com/Shopify/hydrogen/issues/1879

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Before submitting the PR, please make sure you do the following:

• [x] Read the Contributing Guidelines
• [x] Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123)
• [x] Update docs in this repository according to your change
• [x] Run yarn changeset add if this PR cause a version bump based on Keep a Changelog and adheres to Semantic Versioning

[rennyG]

@blittle make sure you tophat this on .dev before shipping

[shopify[bot]]

Oxygen deployed a preview of your small-fixes branch. Details:

Storefront	Status	Preview link	Deployment details	Last update (UTC)
optimistic-cart-ui	✅ Successful (Logs)	Preview deployment	Inspect deployment	May 24, 2024 7:55 PM
Skeleton (skeleton.hydrogen.shop)	✅ Successful (Logs)	Preview deployment	Inspect deployment	May 24, 2024 7:55 PM
subscriptions	✅ Successful (Logs)	Preview deployment	Inspect deployment	May 24, 2024 7:55 PM
third-party-queries-caching	✅ Successful (Logs)	Preview deployment	Inspect deployment	May 24, 2024 7:55 PM
custom-cart-method	✅ Successful (Logs)	Preview deployment	Inspect deployment	May 24, 2024 7:55 PM
vite	✅ Successful (Logs)	Preview deployment	Inspect deployment	May 24, 2024 7:55 PM

Learn more about Hydrogen's GitHub integration.

[github-actions[bot]]

We detected some changes in packages/*/package.json or packages/*/src, and there are no updates in the .changeset. If the changes are user-facing and should cause a version bump, run npm run changeset add to track your changes and include them in the next release CHANGELOG. If you are making simple updates to examples or documentation, you do not need to add a changeset.