[BUG] preview pane is corrupted when `LANG=ja_JP.UTF-8`

[natsukium]

Describe the bug When the LANG environment variable is set to ja_JP.UTF-8, the preview pane becomes corrupted. I'm not familiar with the localization, so I can't determine the exact cause, but this bug is reproducible in all environments I've tested. I haven't tried it, but it's possible that similar problem may occur with other languages as well. For the time being, a workaround is to launch this extension with LANG=C.UTF-8 gh-dash.

To Reproduce

1. launch gh dash with LANG=ja_JP.UTF-8 gh-dash
2. open the preview pane

Expected behavior A clear and concise description of what you expected to happen.

Screenshots expected: with LANG=C.UTF-8

actual: with LANG=ja_JP.UTF-8

Desktop (please complete the following information):

• OS: Linux (NixOS, Ubuntu) and macOS
• Terminal Emulator: Kitty, Alacritty, WezTerm, foot, Terminal.app(Mac), Windows Terminal
• font: Hackgen, Hack, FiraCode (with NerdFont)