improv(editPopup): common ignorable bufname for snippet editor

[DrKGD]

Checklist

• [x] Used only camelCase variable names.
• [x] If functionality is added or modified, also made respective changes to the README.md (the .txt file is auto-generated and does not need to be modified).
• [x] Used conventional commits keywords.

I'd like to prevent my statusline plugin (heirline) to not display a winbar onto the snippet editor.

At the moment this is already implemented for "New Snippets" , but I dont really find any other reasonable key to leverage on (as buftype "nofile" is shared with most of plugin buffers and filetype is not really an option)

[chrisgrieser]

Makes sense. Could you fix the minor nit? Then I can merge it. (ignore the conventional-commits test, it does not recognize improv, which I still need to add)

[chrisgrieser]

thanks!