Fixes full version download test

The test DownloadsLatestFullVersion needs to extract the root directory
to ensure that it is properly cleaned up after the test runs, so that
the test can run multiple times without error.

test/Velopack.Tests/UpdateManagerTests.cs

@@ -535,6 +535,7 @@ public class UpdateManagerTests
         Skip.If(VelopackRuntimeInfo.IsLinux);
         using var logger = _output.BuildLoggerFor<UpdateManagerTests>();
         using var _1 = TempUtil.GetTempDirectory(out var packagesDir);
+        using var _2 = TempUtil.GetTempDirectory(out var rootDir);
         var repo = new FakeFixtureRepository(id, true);
         var source = new SimpleWebSource("http://any.com", repo);
 
@@ -553,7 +554,7 @@ public class UpdateManagerTests
             fromVersion,
             packagesDir,
             null,
-            null,
+            rootDir,
             updateExe,
             null,
             logger.ToVelopackLogger());