dev-python/graphviz: enable py.3.14, fix py3.14 tests

Use upstream patch to fix tests for Python 3.14

Signed-off-by: Sergey Torokhov <torokhov-s-a@yandex.ru>
Part-of: https://github.com/gentoo/gentoo/pull/44245
Closes: https://github.com/gentoo/gentoo/pull/44245
Signed-off-by: Sam James <sam@gentoo.org>

dev-python/graphviz/files/graphviz-0.21_fix_python3_14_tests.patch

@@ -0,0 +1,23 @@
+From 7e0fae6d28792a628a25cadd4ec1582c7351a7a3 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Mark=C3=A9ta=20Cal=C3=A1bkov=C3=A1?=
+ <meggy.calabkova@gmail.com>
+Date: Tue, 9 Sep 2025 16:26:28 +0200
+Subject: [PATCH] fix tests on Python 3.14
+
+---
+ tests/test_quoting.py | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/tests/test_quoting.py b/tests/test_quoting.py
+index 3692d38a12..9dbe45ca50 100644
+--- a/tests/test_quoting.py
++++ b/tests/test_quoting.py
+@@ -17,7 +17,7 @@ def test_deprecated_escape(recwarn, char):
+     assert len(recwarn) == 1
+     w = recwarn.pop(DeprecationWarning if sys.version_info < (3, 12)
+                     else SyntaxWarning)
+-    assert str(w.message).startswith('invalid escape sequence')
++    assert 'invalid escape sequence' in str(w.message)
+ 
+     assert escape == f'\\{char}'
+     assert quoting.quote(escape) == f'"\\{char}"'

dev-python/graphviz/graphviz-0.21.ebuild

@@ -4,7 +4,7 @@
 EAPI=8
 
 DISTUTILS_USE_PEP517=setuptools
-PYTHON_COMPAT=( pypy3_11 python3_{11..13} )
+PYTHON_COMPAT=( pypy3_11 python3_{11..14} )
 
 inherit distutils-r1
 
@@ -34,6 +34,8 @@ BDEPEND="
 	)
 "
 
+PATCHES=( "${FILESDIR}/${P}_fix_python3_14_tests.patch" )
+
 distutils_enable_tests pytest
 
 src_prepare() {