Update futures pinned version in fake_with_deps package

The latest version has python_requires in `setup.py`, which fixes
failing test_realistic_complex_sub_dependencies on the latest `setuptools`.

tests/test_data/packages/fake_with_deps/setup.py

@@ -9,7 +9,7 @@
         "cornice<1.1,>=1.0.0",
         "enum34<1.1.7,>=1.0.4",
         "six>1.5,<=1.8",
-        "futures<3.1,>=3.0.3",
+        "futures<3.4,>=3.0.3",
         "ipaddress<1.1,>=1.0.16",
         "jsonschema<3.0,>=2.4.0",
         "pyramid<1.6,>=1.5.7",

tox.ini

@@ -11,8 +11,6 @@ extras =
     testing
     coverage: coverage
 deps =
-    # due to broken CI, to be removed as soon as it is fixed, compare https://github.com/pypa/setuptools/issues/2687
-    setuptools<57
     pipprevious: pip==20.3.*
     piplatest: pip
     pipmain: -e git+https://github.com/pypa/pip.git@main#egg=pip