ci: run --pyoxidized tests on Windows stable

ci: run --pyoxidized tests on Windows

They still have numerous failure, but at least we can start fixing them now.

Differential Revision: https://phab.mercurial-scm.org/D11278

--- a/contrib/heptapod-ci.yml	Tue Aug 10 12:56:32 2021 +0200
+++ b/contrib/heptapod-ci.yml	Mon Aug 09 00:49:50 2021 -0400
@@ -176,3 +176,13 @@
         TEST_HGMODULEPOLICY: "c"
         RUNTEST_ARGS: "--blacklist C:/Temp/check-tests.txt"
         PYTHON: py -3
+
+windows-py3-pyox:
+    <<: *windows_runtests
+    when: manual
+    tags:
+      - windows
+    variables:
+        TEST_HGMODULEPOLICY: "c"
+        RUNTEST_ARGS: "--blacklist C:/Temp/check-tests.txt --pyoxidized"
+        PYTHON: py -3