remove redundant import

Author: rochala

compiler/src/dotty/tools/repl/transform/CollectTopLevelImports.scala

@@ -5,7 +5,6 @@ import dotty.tools.dotc.ast.untpd
 import dotty.tools.dotc.core.Contexts._
 import dotty.tools.dotc.core.Names.Name
 import dotty.tools.dotc.core.Phases.Phase
-import dotty.tools.dotc.util.SourcePosition
 import dotty.tools.dotc.core.StdNames.ScalaTermNames