fix: fallbacks for non-react client

[Benehiko]

Related Issue or Design Document

useId does not fallback now when the React import is null. This means express cannot use the @ory/elements-markup package.

TypeError: Cannot read properties of null (reading 'useId')
    at ln (/home/benehiko/Github/elements/packages/markup/dist/index.umd.js:29:1199)
    at Nav$1 (/home/benehiko/Github/elements/packages/markup/dist/index.umd.js:69:17981)
    at Nav (/home/benehiko/Github/elements/packages/markup/dist/index.umd.js:173:19625)
    at navigationMenu (/home/benehiko/Github/kratos-selfservice-ui-node/src/pkg/ui.ts:83:13)
    at /home/benehiko/Github/kratos-selfservice-ui-node/src/routes/welcome.ts:33:26
    at step (/home/benehiko/Github/kratos-selfservice-ui-node/src/routes/welcome.ts:33:23)
    at Object.next (/home/benehiko/Github/kratos-selfservice-ui-node/src/routes/welcome.ts:14:53)
    at fulfilled (/home/benehiko/Github/kratos-selfservice-ui-node/src/routes/welcome.ts:5:58)
    at processTicksAndRejections (node:internal/process/task_queues:95:5)
[nodemon] app crashed - waiting for file changes before starting...

Checklist

• [ ] I have read the contributing guidelines and signed the CLA.
• [ ] I have referenced an issue containing the design document if my change introduces a new feature.
• [ ] I have read the security policy.
• [ ] I confirm that this pull request does not address a security vulnerability. If this pull request addresses a security vulnerability, I confirm that I got approval (please contact security@ory.sh) from the maintainers to push the changes.
• [ ] I have added tests that prove my fix is effective or that my feature works.
• [ ] I have added the necessary documentation within the code base (if appropriate).

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