bug: exit from insert-mode duplicates inserted text ending with [](){} chars

[daveHylde]

Check the following:

• [x] I have tried setting vscode-neovim.neovimClean in VSCode settings and restarting VSCode.
• [x] I have read the vscode-neovim docs.
• [x] I have searched existing (closed!) issues.

Neovim version (nvim -v)

1.18.24

Operating system/version

NixOS 25.05

Problem (including log messages)

When writing anything in insert-mode and ending with one of these chars: ()[]{} then whatever was written will be duplicated.

Steps To Reproduce

1. Insert-mode
2. write anything and end with one of these: {}
3. ESC

Expected Behavior

Should not duplicate what was written