Don't check parents in ClassLoaderCacheTest

This check doesn't actually make sense anymore with the new
ClassLoaderCache. In the old ClassLoaderCache, there were separate
layers for the snapshots and regular jars.  The test was verifying that
only the snapshot layer was invalidated but now there is just one layer.

main-command/src/test/scala/sbt/internal/ClassLoaderCacheTest.scala

@@ -48,7 +48,6 @@ class ClassLoaderCacheTest extends FlatSpec with Matchers {
       IO.setModifiedTimeOrFalse(snapshotJar, System.currentTimeMillis + 5000L)
       val secondLoader = cache.get(jarClassPath)
       assert(initLoader != secondLoader)
-      assert(initLoader.getParent == secondLoader.getParent)
       assert(cache.get(jarClassPath) == secondLoader)
       assert(cache.get(jarClassPath) != initLoader)
     }