python: add pythonRemoveTestsDirHook

This will automatically remove a top-level "tests"
directory from being installed.

pkgs/development/interpreters/python/hooks/python-remove-tests-dir-hook.sh

@@ -0,0 +1,15 @@
+# Clean up top-level tests directory in site-package installation.
+echo "Sourcing python-remove-tests-dir-hook"
+
+pythonRemoveTestsDir() {
+    echo "Executing pythonRemoveTestsDir"
+
+    rm -rf $out/@pythonSitePackages@/tests
+
+    echo "Finished executing pythonRemoveTestsDir"
+}
+
+if [ -z "${dontUsePythonRemoveTestsDir-}" ]; then
+    postFixupHooks+=(pythonRemoveTestsDir)
+fi
+