Apply suggestions from code review

Co-authored-by: Carlos Cordoba <ccordoba12@gmail.com>

pyproject.toml

@@ -3,4 +3,7 @@ requires = [
     "setuptools>=42",
     "packaging",
 ]
-build-backend = "setuptools.build_meta"
+
+# We're not ready yet to build Spyder with the setuptools backend, but we're
+# leaving this for the future.
+# build-backend = "setuptools.build_meta"