bug: lazy tries to load plugins that aren't installed

[LostNeophyte]

Did you check docs and existing issues?

• I have read all the lazy docs
• I have searched the existing issues of lazy
• I have searched the exsiting issues of the plugin I have a problem with

Neovim version (nvim -v)

NVIM v0.9.0-dev+519-g2d8bbe468

Operating system/version

Fedora 36

Describe the bug

lazy tries to load plugins that aren't installed (when automatic installation is disabled or there's no internet)

Steps To Reproduce

1. nvim -u repro.lua

2.  Failed to run `config` for which-key.nvim                                                                                                                                                                                                       
    /tmp/repro.lua:30: module 'which-key' not found:
   

Expected Behavior

no errors, config function should not be called when the plugin is not installed

Repro

-- DO NOT change the paths and don't remove the colorscheme
local root = vim.fn.fnamemodify("./.repro", ":p")

-- set stdpaths to use .repro
for _, name in ipairs({ "config", "data", "state", "cache" }) do
  vim.env[("XDG_%s_HOME"):format(name:upper())] = root .. "/" .. name
end

-- bootstrap lazy
local lazypath = root .. "/plugins/lazy.nvim"
if not vim.loop.fs_stat(lazypath) then
  vim.fn.system({
    "git",
    "clone",
    "--filter=blob:none",
    "--single-branch",
    "https://github.com/folke/lazy.nvim.git",
    lazypath,
  })
end
vim.opt.runtimepath:prepend(lazypath)

-- install plugins
local plugins = {
  "folke/tokyonight.nvim",
  {
    "folke/which-key.nvim",
    -- should not be called when the plugin is not installed
    config = function()
      require("which-key")
    end,
  },
  -- add any other plugins here
}
require("lazy").setup(plugins, {
  root = root .. "/plugins",
  install = {
    missing = false,
  },
})

vim.cmd.colorscheme("habamax")
pcall(function()
  vim.cmd.colorscheme("tokyonight")
end)