Added punkt dependency to Dockerfile.

samples/tools/autogenbench/autogenbench/res/Dockerfile

@@ -41,3 +41,4 @@ RUN /usr/bin/echo -e "import easyocr\nreader = easyocr.Reader(['en'])" | python
 
 # Webarena
 RUN pip install beartype aiolimiter
+RUN /usr/bin/echo -e "import nltk\nnltk.download('punkt')" | python