port_publish: read gh's and Kira's output as UTF-8

gh() and kira() ran subprocess with text=True and no encoding, so on
Windows Python decoded their UTF-8 output with the code page: an issue
body's → came back as →, and merged() wrote it back on the next update.
Follows d3grando's review on #3587.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

tests/test_port_publish.py

@@ -1,3 +1,4 @@
+import json
 from pathlib import Path
 import unittest
 from unittest import mock
@@ -93,6 +94,16 @@ class PublishTests(unittest.TestCase):
         self.assertIn("- [ ] #101 [26.4] Protocol", bodies["[26.4] Port to Minecraft 26.4"])
         self.assertFalse([c for c in calls if c[:2] == ("label", "create")])
 
+    def test_gh_and_kira_read_utf8_whatever_the_code_page(self):
+        # gh and node print UTF-8; without an encoding, Windows decodes it with the code page (cp1252 here).
+        def run(command, **kwargs):
+            out = json.dumps({"body": "a → b"}, ensure_ascii=False).encode("utf-8")
+            return mock.Mock(stdout=out.decode(kwargs.get("encoding") or "cp1252"))
+
+        with mock.patch.object(publish.subprocess, "run", side_effect=run):
+            self.assertEqual(json.loads(publish.gh("issue", "view"))["body"], "a → b")
+            self.assertEqual(publish.kira("board_list", {})["body"], "a → b")
+
 
 if __name__ == "__main__":
     unittest.main()

tools/port_publish.py

@@ -191,7 +191,8 @@ def plan(report, diff, store_path, open_issues):
 # --- GitHub and Kira (only with --yes) ---------------------------------------------------------------------
 
 def gh(*args):
-    return subprocess.run(["gh", *args], capture_output=True, text=True, check=True).stdout
+    # gh prints UTF-8, whatever the system's code page.
+    return subprocess.run(["gh", *args], capture_output=True, encoding="utf-8", check=True).stdout
 
 
 def open_version_port_issues():
@@ -241,7 +242,7 @@ def issue(action, name, text, number, new):
 
 def kira(tool, arguments):
     return json.loads(subprocess.run(["node", str(KIRA), tool, json.dumps(arguments)], capture_output=True,
-                                     text=True, check=True).stdout or "null")
+                                     encoding="utf-8", check=True).stdout or "null")
 
 
 def kira_card(new, url):