refactor(io): remove dead code from PgnParser.importGameContext

Remove unnecessary if/else check (lines 49-50) that could never be true.
DefaultRules.applyMove always calls .withMove(move) on the context,
so finalCtx.moves is always populated when game.moves.nonEmpty.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

modules/io/src/main/scala/de/nowchess/io/pgn/PgnParser.scala

@@ -45,11 +45,7 @@ object PgnParser:
       }
       errors match
         case Some(err) => Left(err)
-        case None =>
+        case None => Right(finalCtx)
-          if finalCtx.moves.isEmpty && game.moves.nonEmpty then
-            Left("No moves were parsed from the PGN")
-          else
-            Right(finalCtx)
     }
 
   /** Parse a complete PGN text into a PgnGame with headers and moves.