If the location of a local plugin is a symlink, `PackerSync` generates an error

nvim --version: 0.7.2
git --version: 2.37.3
Operating system/version: macOS Monterey 12.3.1
Terminal name/version: kitty 0.26.1

Steps to reproduce

Starting at 2b0af3b20f3ddf18ee2d5022dd80635dbc35eb1c, if the path given to a local plugin is a symlink, the following error occurs if PackerSync is run and the symlink in the packer directory exists:

[packer.nvim] [ERROR 18:15:15] async.lua:20: Error in coroutine: ...packer/opt/packer.nvim/lua/packer/plugin_types/local.lua:56: attempt to index a nil value

In my setup, I'm using fzf installed with Homebrew, so the main path is a symlink to the "cellar" binary:

  use({
    '/opt/homebrew/opt/fzf',
    cond = function()
      return vim.fn.executable('fzf') == 1
    end,
  })

/opt/homebrew/opt/fzf is a symlink pointing (currently) to /opt/homebrew/Cellar/fzf/0.33.0.

I added some print() statements after line 53 of local.lua:

      local resolved_path = vim.fn.resolve(to)
      print('From: ' .. from)
      print('To: ' .. to)
      print('Resolved: ' .. resolved_path)

And when the updater code is run, it gives the following output

From: /opt/homebrew/opt/fzf
To: /Users/bryan/.local/share/nvim/site/pack/packer/opt/fzf
Resolved: /opt/homebrew/Cellar/fzf/0.33.0

Actual behaviour

An error occurs if the symlink in the packer directory exists:

[packer.nvim] [ERROR 18:15:15] async.lua:20: Error in coroutine: ...packer/opt/packer.nvim/lua/packer/plugin_types/local.lua:56: attempt to index a nil value

Expected behaviour

If the symlink exists and points to the correct directory, nothing happens. If the symlink exists and points to the wrong directory, it is updated. If the symlink does not exist, it is created.

wbthomason / packer.nvim