fix isDraggingInternally reset logic

[BitPhinix]

Description
Currently isDraggingInternally is only reset if the onDrop/onDragEnd events aren't handled by the respective "external" editable event handlers. This potentially causes isDraggingInternally to stay true even though the user isn't dragging anymore blocking onDOMSelectionChange thus preventing the user from selecting anything inside the editor.

Context
This pr simply ensues isDraggingInternally is always reset onDrop/onDragEnd

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: f8a2d9c

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

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR