Hotfix for StarterKit installs w/ Plugins that add to source/

[EvanLovely]

To recreate:

composer create-project pattern-lab/edition-drupal-standard

Select any starterkit (preferably pattern-lab/starterkit-twig-drupal-minimal) and you'll see this error (ran with -vvv):

I hunted the error down to Fetch.php's mirrorDist() seen here.

// if source directory isn't empty ask if it's ok to nuke what's there
if (!$emptyDir) {

  $prompt    = "a starterkit is already installed. merge the new files with it or replace it?";
  $options   = "M/r";
  $input     = Console::promptInput($prompt,$options);
  $fsOptions = ($input == "r") ? array("delete" => true, "override" => true) : array("delete" => false, "override" => false);

}

// mirror dist to source
Console::writeInfo("installing the starterkit files...");
$fs = new Filesystem();
$fs->mirror($tempDirDist, $sourceDir, null, $options); // ERROR HAPPENS HERE
Console::writeInfo("starterkit files have been installed...");

It's always worked before because the code in if (!$emptyDir) was always ran, which set $options to "M/r". When that conditional doesn't run it's code block, we get the cause of the error: Undefined variable: options. I can tell that the $options set is for Console::promptInput() and isn't intended for $fs->mirror(), because the Symfony Filesystem mirror function wants $options to be an array and not a string. So basically this PR just removes the $options from $fs->mirror():

- $fs->mirror($tempDirDist, $sourceDir, null, $options);
+ $fs->mirror($tempDirDist, $sourceDir, null);

Would be really great to get this soon as this prevents the Drupal Edition from getting launched!! 🙏

[dmolsen]

This was a bad merge on my part. The name of the var should have been $fsOptions. It will be making a re-appearance in v0.7.3 of core.