Drop override in SeqFactory

Another method that was added for the typesafety demonstration, which should be removed now.

scala2-library-cc/src/scala/collection/Factory.scala

@@ -296,21 +296,12 @@ object IterableFactory {
   }
 }
 
-// !!! Needed to add this separate trait
-//trait FreeSeqFactory[+CC[A]] extends IterableFactory[CC]:
-//  def from[A](source: IterableOnce[A]^): CC[A]
-//  override def apply[A](elems: A*): CC[A]
-
-// type FreeSeqFactory[+CC[A] <: SeqOps[A, Seq, Seq[A]]] = SeqFactory[CC]
-
 /**
   * @tparam CC Collection type constructor (e.g. `List`)
   */
 trait SeqFactory[+CC[A] <: SeqOps[A, Seq, Seq[A]]] extends IterableFactory[CC] {
   import SeqFactory.UnapplySeqWrapper
   final def unapplySeq[A](x: CC[A] @uncheckedVariance): UnapplySeqWrapper[A] = new UnapplySeqWrapper(x) // TODO is uncheckedVariance sound here?
-  def from[A](source: IterableOnce[A]^): CC[A]
-  override def apply[A](elems: A*): CC[A] = from(elems)
 }
 
 object SeqFactory {