After merging guardian/bridget#259, use the new `getLoggedInUserEmail` Bridget method to [populate the email signup form](https://github.com/guardian/dotcom-rendering/blob/e505fed9aa41974307815a255de3c035a89b940a/dotcom-rendering/src/components/SecureSignup.island.tsx#L322-L329)
After merging guardian/bridget#259, use the new
getLoggedInUserEmailBridget method to populate the email signup form