Code block cursor confusion problem

[Ran Luo]

• Searched existing issues to avoid creating duplicates.

• Confirmed that it can be reproduced in muya.

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Describe the bug
Typing too fast in a codeblock causes a cursor error

To Reproduce
Steps to reproduce the behavior:

1. Create a javascript code block
2. type JS codes bellow:

const a = '4'
function add(){}

Expected behavior
The code is entered normally

Actual behavior

Uncaught DOMException: Index or size is negative or greater than the allowed amount

Operation System and Browser version (please complete the following information):

• OS: [e.g. macOS 13.5 (22G74)]
• Browser: firefox only

Muya Version
e.g: 0.10.11