PYTHON-4070 Add setuptools as dep for test target (#1451)

Author: caseyclements

tox.ini

@@ -48,6 +48,8 @@ labels = # Use labels and -m instead of -e so that tox -m <label> fails instantl
 description = run base set of unit tests with no extra functionality
 extras =
     test
+deps =
+    setuptools
 allowlist_externals =
     .evergreen/check-c-extensions.sh
 commands =