Update ssrFunctionNodeVersion to use Node 18

[adamraya]

Description

MRT only supports bundles running Node 18. The PR updates the ssrFunctionNodeVersion to use Node 18.

Types of Changes

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Documentation update
• Breaking change (could cause existing functionality to not work as expected)
• Other changes (non-breaking changes that does not fit any of the above)

Breaking changes include:

• Removing a public function or component or prop
• Adding a required argument to a function
• Changing the data type of a function parameter or return value
• Adding a new peer dependency to package.json

Changes

• Updated ssrFunctionNodeVersion to Node 18.

How to Test-Drive This PR

• Generate a project and verify that the ssrFunctionNodeVersion is using Node 18.

GENERATOR_PRESET=retail-react-app-demo node packages/pwa-kit-create-app/scripts/create-mobify-app-dev.js —outputDir ~/generated-project-demo

Checklists

General

• Changes are covered by test cases
• CHANGELOG.md updated with a short description of changes (not required for documentation updates)

Accessibility Compliance

You must check off all items in one of the follow two lists:

• There are no changes to UI

or...

• Changes were tested with a Screen Reader (iOS VoiceOver or Android Talkback) and had no issues
• Changes comply with WCAG 2.0 guidelines levels A and AA
• Changes to common UI patterns and interactions comply with WAI-ARIA best practices

Localization

• Changes include a UI text update in the Retail React App (which requires translation)