Don't convert the implicit failure

Author: dwijnand

compiler/src/dotty/tools/dotc/typer/Implicits.scala

@@ -1346,8 +1346,6 @@ trait Implicits:
               case fail: SearchFailure =>
                 if fail eq ImplicitSearchTooLargeFailure then
                   fail
-                else if fail.isAmbiguous then
-                  rank(remaining, found, NoMatchingImplicitsFailure :: rfailures)
                 else rank(remaining, found, fail :: rfailures)
               case best: SearchSuccess =>
                 if (ctx.mode.is(Mode.ImplicitExploration) || isCoherent)