Remove unused import from bindiff.py

Remove spurious import statement for 'st' from turtle module.

Author: RobinDavid

src/bindiff/bindiff.py

@@ -5,7 +5,6 @@
 import subprocess
 import tempfile
 from pathlib import Path
-from turtle import st
 from typing import Union, Optional
 
 from binexport import ProgramBinExport, FunctionBinExport, BasicBlockBinExport, InstructionBinExport