nixpkgs/neovim: set shell to /bin/sh

When using a non-posix shell as $SHELL, ! commands always fail

.config/nixpkgs/neovim/mappings.lua

@@ -61,7 +61,7 @@ vim.keymap.set('n', '<Leader>ut', '<cmd>UndotreeToggle<CR>', opts)
 
 -- opening terminals
 vim.keymap.set('n', '<Leader>tv', '<cmd>vsp term://$SHELL<CR>', opts)
-vim.keymap.set('n', '<Leader>to', '<cmd>term<CR>', opts)
+vim.keymap.set('n', '<Leader>to', '<cmd>term $SHELL<CR>', opts)
 
 -- delete buffer
 vim.keymap.set('n', '<Leader>q', '<cmd>lua MiniBufremove.delete()<CR>', opts)

.config/nixpkgs/neovim/settings.lua

@@ -51,3 +51,5 @@ vim.o.mouse = false
 vim.o.foldmethod = 'expr'
 vim.o.foldexpr = 'nvim_treesitter#foldexpr()'
 vim.o.foldenable = false
+
+vim.o.shell = '/bin/sh'