Fixed #32713, Fixed CVE-2021-32052 -- Prevented newlines and tabs from being accepted in URLValidator on Python 3.9.5+.

In Python 3.9.5+ urllib.parse() automatically removes ASCII newlines
and tabs from URLs [1, 2]. Unfortunately it created an issue in
the URLValidator. URLValidator uses urllib.urlsplit() and
urllib.urlunsplit() for creating a URL variant with Punycode which no
longer contains newlines and tabs in Python 3.9.5+. As a consequence,
the regular expression matched the URL (without unsafe characters) and
the source value (with unsafe characters) was considered valid.

[1] https://bugs.python.org/issue43882 and
[2] 76cd81d603

docs/releases/index.txt

@@ -41,6 +41,7 @@ versions of the documentation contain the release notes for any later releases.
 .. toctree::
    :maxdepth: 1
 
+   3.1.10
    3.1.9
    3.1.8
    3.1.7
@@ -78,6 +79,7 @@ versions of the documentation contain the release notes for any later releases.
 .. toctree::
    :maxdepth: 1
 
+   2.2.22
    2.2.21
    2.2.20
    2.2.19