React: Fix missing framework options in shim

[tmeasday]

Closes #21632

What I did

Don't assume presets.apply('frameworkOptions') will return an object, as we explicitly return null in some cases:

storybook/code/lib/core-server/src/presets/common-preset.ts

Line 208 in bc77248

return null;

How to test

Comment out framework.options in a vite sandbox.

Checklist

• Make sure your changes are tested (stories and/or unit, integration, or end-to-end tests)
• Make sure to add/update documentation regarding your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Maintainers

• If this PR should be tested against many or all sandboxes,
  make sure to add the ci:merged or ci:daily GH label to it.
• Make sure this PR contains one of the labels below.

["cleanup", "BREAKING CHANGE", "feature request", "bug", "documentation", "maintenance", "dependencies", "other"]

[tmeasday]

@ndelangen an alternative solution here would be to always return an object for the frameworkOptions. Then we could call presets.apply('frameworkOptions', {}) and know we'll get an object back (we don't currently due to the common preset linked above).

[shilman]

LGTM!