Add workaround for PGO failures with Heroku-22's libexpat

Author: edmorley

builds/Dockerfile

@@ -15,4 +15,4 @@ RUN apt-get update --error-on=any \
     && rm -rf /var/lib/apt/lists/*
 
 WORKDIR /tmp
-COPY build_python_runtime.sh .
+COPY build_python_runtime.sh python-3.13-ubuntu-22.04-libexpat-workaround.patch .

builds/build_python_runtime.sh

@@ -90,6 +90,14 @@ gpg --batch --verify python.tgz.asc python.tgz
 tar --extract --file python.tgz --strip-components=1 --directory "${SRC_DIR}"
 cd "${SRC_DIR}"
 
+# Work around PGO profile test failures with Python 3.13 on Ubuntu 22.04, due to the tests
+# checking the raw libexpat version which doesn't account for Ubuntu backports:
+# https://github.com/heroku/heroku-buildpack-python/pull/1661#issuecomment-2405259352
+# https://github.com/python/cpython/issues/125067
+if [[ "${PYTHON_MAJOR_VERSION}" == "3.13" && "${STACK}" == "heroku-22" ]]; then
+	patch -p1 </tmp/python-3.13-ubuntu-22.04-libexpat-workaround.patch
+fi
+
 # Aim to keep this roughly consistent with the options used in the Python Docker images,
 # for maximum compatibility / most battle-tested build configuration:
 # https://github.com/docker-library/python

builds/python-3.13-ubuntu-22.04-libexpat-workaround.patch

@@ -0,0 +1,24 @@
+diff --git a/Lib/test/test_xml_etree.py b/Lib/test/test_xml_etree.py
+index ebec9d8f18a..385735c1e18 100644
+--- a/Lib/test/test_xml_etree.py
++++ b/Lib/test/test_xml_etree.py
+@@ -1504,9 +1504,11 @@ def test_simple_xml(self, chunk_size=None, flush=False):
+         self.assert_event_tags(parser, [('end', 'root')])
+         self.assertIsNone(parser.close())
+ 
++    @unittest.skip('Work around: https://github.com/python/cpython/issues/125067')
+     def test_simple_xml_chunk_1(self):
+         self.test_simple_xml(chunk_size=1, flush=True)
+ 
++    @unittest.skip('Work around: https://github.com/python/cpython/issues/125067')
+     def test_simple_xml_chunk_5(self):
+         self.test_simple_xml(chunk_size=5, flush=True)
+ 
+@@ -1731,6 +1733,7 @@ def test_flush_reparse_deferral_enabled(self):
+ 
+         self.assert_event_tags(parser, [('end', 'doc')])
+ 
++    @unittest.skip('Work around: https://github.com/python/cpython/issues/125067')
+     def test_flush_reparse_deferral_disabled(self):
+         parser = ET.XMLPullParser(events=('start', 'end'))
+