Drop explicit graphviz dependency.

Author: superdosh

pyproject.toml

@@ -22,7 +22,6 @@ dependencies = [
     "scikit-learn>=1.5.0,<2.0.0",
     "pandas>=2.2.2,<4",
     "modelbench[composer] @ git+https://github.com/mlcommons/modelbench.git",
-    "graphviz>=0.20,<1",
     # the below 4 are tied to the Dockerfile.mlflow versions; need to be upgraded together
     "mlflow[auth]==3.7.0",
     "psycopg2-binary==2.9.11",