CocCommand cSpell.toggleEnableSpellChecker does not work

[hereGittyGitty]

Describe the bug
When calling CocCommand cSpell.toggleEnableSpellChecker, spell checking is
not toggled. Instead the following error message is shown:

[coc.nvim]: Unable to locate workspace folder configuration for undefined

To Reproduce
Steps to reproduce the behavior:

1. Start neovim with coc.nvim and coc-spell-checker installed
2. Run the command CocCommand cSpell.toggleEnableSpellChecker
3. See the error message: [coc.nvim]: Unable to locate workspace folder configuration for undefined

Expected behavior
Spell checking is enabled/disabled.

Screenshots
This little gif shows what is happening:

minimal config
neovim was started like this

VIMRUNTIME=/usr/local/src/neovim/runtime /usr/local/src/neovim/build/bin/nvim
--clean -u /usr/local/src/neovim_minimal_stuff/minimal_init.vim
/usr/local/src/neovim_minimal_stuff/minimal.txt

with a minimal config containing

set nocompatible

let g:coc_config_home = '/usr/local/src/neovim_minimal_stuff/.config/nvim'
let g:coc_data_home = '/usr/local/src/neovim_minimal_stuff/.config/coc'

set runtimepath+=/usr/local/src/neovim_minimal_stuff/coc.nvim

filetype plugin indent on

nvim --version shows

NVIM v0.9.0-dev-588+g99cf11128
Build type: Release
LuaJIT 2.1.0-beta3
Compiled by lorenz@chicken

Features: +acl +iconv +tui
See ":help feature-compile"

   system vimrc file: "$VIM/sysinit.vim"
  fall-back for $VIM: "/usr/local/share/nvim"

Run :checkhealth for more info

coc.nvim is on the release branch, holding the commit

commit 95b43f67147391cf2c69e550bd001b742781d226

coc-spell-checker was just installed with CocInstall coc-spell-checker

My coc-settings.json contains the following entry

{
  "cSpell.enabled": true,
}

Desktop (please complete the following information):

• OS: GNU/Linux

Log:
CocOpenLog opens the following log file after CocCommand cSpell.toggleEnableSpellChecker was invoked:

2022-12-31T12:41:45.900 INFO (pid:95200) [plugin] - coc.nvim initialized with node: v18.12.1 after 130
2022-12-31T12:41:45.914 WARN (pid:95200) [workspace] - workspace.createStatusBarItem is deprecated, please use window.createStatusBarItem instead. 
    at t.initStatusBar (/usr/local/src/neovim_minimal_stuff/.config/coc/extensions/node_modules/coc-spell-checker/out/index.js:1:156009)
    at t.activate (/usr/local/src/neovim_minimal_stuff/.config/coc/extensions/node_modules/coc-spell-checker/out/index.js:1:23162)
2022-12-31T12:41:45.919 INFO (pid:95200) [language-client-index] - Language server "cSpell" started with 95212
2022-12-31T12:41:57.862 INFO (pid:95200) [attach] - receive notification: openLog []
2022-12-31T12:41:57.875 INFO (pid:95200) [attach] - receive notification: doAutocmd [ 1 ]
2022-12-31T12:42:00.471 INFO (pid:95200) [attach] - receive notification: doAutocmd [ 1 ]
2022-12-31T12:42:14.774 INFO (pid:95200) [attach] - Request action: commandList [ 'cSpe', 'CocCommand cSpe', 15 ]
2022-12-31T12:42:19.015 INFO (pid:95200) [attach] - receive notification: runCommand [ 'cSpell.toggleEnableSpellChecker' ]
2022-12-31T12:42:19.019 ERROR (pid:95200) [configurations] - Unable to locate workspace folder configuration undefined Error
    at Object.update (/usr/local/src/neovim_minimal_stuff/coc.nvim/build/index.js:152:6903)
    at t.setSettingInVSConfig (/usr/local/src/neovim_minimal_stuff/.config/coc/extensions/node_modules/coc-spell-checker/out/index.js:1:16962)
    at t.toggleEnableSpellChecker (/usr/local/src/neovim_minimal_stuff/.config/coc/extensions/node_modules/coc-spell-checker/out/index.js:1:29162)
    at Kk.execute (/usr/local/src/neovim_minimal_stuff/coc.nvim/build/index.js:69:2984)
    at Qk.executeCommand (/usr/local/src/neovim_minimal_stuff/coc.nvim/build/index.js:69:4090)
    at Qk.fireCommand (/usr/local/src/neovim_minimal_stuff/coc.nvim/build/index.js:69:4186)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async Nm.runCommand (/usr/local/src/neovim_minimal_stuff/coc.nvim/build/index.js:256:24046)
    at async cb.cocAction (/usr/local/src/neovim_minimal_stuff/coc.nvim/build/index.js:276:46545)
    at async EventEmitter.<anonymous> (/usr/local/src/neovim_minimal_stuff/coc.nvim/build/index.js:276:48151)
2022-12-31T12:42:22.243 INFO (pid:95200) [attach] - receive notification: openLog []

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