upgrade requirement to construct==2.10.68

Author: timrid

setup.py

@@ -21,7 +21,7 @@
     url="https://github.com/timrid/construct-typing",
     author="Tim Riddermann",
     python_requires=">=3.7",
-    install_requires=["construct==2.10.67"],
+    install_requires=["construct==2.10.68"],
     keywords=[
         "construct",
         "kaitai",