fix: use ownerDocument to create element

[leoc4e]

Description
Fixed the issue that copying from editable inside iframe does not work
https://github.com/leoc4e/slate/blob/d06706c9e15bbbdd7cdd9a1bbb38c87d37c85ea1/packages/slate-react/src/utils/dom.ts#L66-L70

Issue
Fixes: #4660

Example

Context
The issues is due to getPlainText is returning empty string in iframe.
https://github.com/leoc4e/slate/blob/272ad7ffddae8d1163e395a44dd59f66e2b0f1b0/packages/slate-react/src/plugin/with-react.ts#L191-L192

This is because isDomNode would check if the element is an instance of the ownerDocument.defaultValue.Node
(https://github.com/leoc4e/slate/blob/d06706c9e15bbbdd7cdd9a1bbb38c87d37c85ea1/packages/slate-react/src/utils/dom.ts#L66-L70)
While slate is using default document when creating the element.
This PR change to use the ownerDocument instead

Checks

• The new code matches the existing patterns and styles.
• The tests pass with yarn test.
• The linter passes with yarn lint. (Fix errors with yarn fix.)
• The relevant examples still work. (Run examples with yarn start.)
• You've added a changeset if changing functionality. (Add one with yarn changeset add.)

[changeset-bot]

🦋 Changeset detected

Latest commit: 1154c55

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
slate-react	Patch

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[dylans]

Please add a changeset and then I'll land this. Thanks for the contribution @leoc4e .

The instructions are pretty straightforward for changesets, but if you have any questions just let me know.