Remove date comparison from SelectInstanceCommand

The InstanceComparer that was added as part of microsoft#41 to fix microsoft#40 isn't actually able to solve the problem due to the implementation of the ProcessRecord method in SelectInstanceCommand. InstanceComparer is used to sort instances by version and then date, but when iterating over all instances, the latestInstance variable is only set when the latestInstance date is less than the date of the current instance in the loop.

This completely ignores the previous OrderBy that was done using InstanceComparer. The simplest solution at this point is to always set the latestInstance variable when the Latest flag is set because the collection is already sorted in the desired order and no additional comparisons are necessary.

src/VSSetup.PowerShell/PowerShell/SelectInstanceCommand.cs

@@ -149,10 +149,7 @@ bool Contains(IEnumerable<PackageReference> packages, Func<PackageReference, str
  {
  if (Latest)
  {
- if (latestInstance == null || latestInstance.InstallDate < instance.InstallDate)
- {
- latestInstance = instance;
- }
+ latestInstance = instance;
  }
  else
  {