Fix shopify cookie with leading dot domain

[wizardlyhel]

WHY are these changes introduced?

It looks like checkout is re-assigning _shopify_y and _shopify_s cookie if the domain is not set with a leading period when used with customer privacy api. (Validated issue with hydrogen.shop)

WHAT is this pull request doing?

Make sure leading period is added to cookie domain if not present.

HOW to test your changes?

Post-merge steps

Checklist

• I've read the Contributing Guidelines
• I've considered possible cross-platform impacts (Mac, Linux, Windows)
• I've added a changeset if this PR contains user-facing or noteworthy changes
• I've added tests to cover my changes
• I've added or updated the documentation

[shopify]

Oxygen deployed a preview of your hl-fix-cookie-domain branch. Details:

Storefront	Status	Preview link	Deployment details	Last update (UTC)
custom-cart-method	✅ Successful (Logs)	Preview deployment	Inspect deployment	May 22, 2024 5:35 PM
third-party-queries-caching	✅ Successful (Logs)	Preview deployment	Inspect deployment	May 22, 2024 5:35 PM
subscriptions	✅ Successful (Logs)	Preview deployment	Inspect deployment	May 22, 2024 5:36 PM
Skeleton (skeleton.hydrogen.shop)	✅ Successful (Logs)	Preview deployment	Inspect deployment	May 22, 2024 5:35 PM
optimistic-cart-ui	✅ Successful (Logs)	Preview deployment	Inspect deployment	May 22, 2024 5:36 PM
vite	✅ Successful (Logs)	Preview deployment	Inspect deployment	May 22, 2024 5:36 PM

Learn more about Hydrogen's GitHub integration.

[blittle]

How do we validate this on Hydrogen.shop before merging? Upgrade hydrogen.shop to the next release?

[wizardlyhel]

That is what I was thinking too, upgrade to next for hydrogen.shop