Ensure to call py_repositories

This makes the `rules_python_internal` repository available.

Author: avdv

WORKSPACE

@@ -9,6 +9,10 @@ load("//haskell:repositories.bzl", "rules_haskell_dependencies")
 
 rules_haskell_dependencies()
 
+load("@rules_python//python:repositories.bzl", "py_repositories")
+
+py_repositories()
+
 load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
 
 http_archive(