PEP 453: only remove setuptools once pip drops support for legacy ins…

…talls (#2096)

pep-0453.txt

@@ -647,10 +647,9 @@ detail. Other projects which explicitly require ``setuptools`` must still
 provide an appropriate dependency declaration, rather than assuming
 ``setuptools`` will always be installed alongside ``pip``.
 
-Once pip is able to run ``pip install --upgrade pip`` without needing
-``setuptools`` installed first, then the private copy of ``setuptools``
-will be removed from ``ensurepip`` in subsequent CPython releases.
-
+The private copy of ``setuptools`` will be removed from ``ensurepip``
+once it is no longer needed. This is likely to be at the point when
+``get-pip.py`` stops installing ``setuptools`` by default.
 As long as setuptools is needed, it will be a completely unmodified copy of
 the latest upstream setuptools release, including the ``easy_install``
 script if the upstream setuptools continues to include it. The installation