test: gate offline release journey deterministically

tests/e2e/fake_gitea.py

@@ -22,6 +22,7 @@ class FakeGiteaServer(ThreadingHTTPServer):
     def __init__(self, address: tuple[str, int]):
         super().__init__(address, FakeGiteaHandler)
         self.created_issues: list[dict] = []
+        self.issue_creation_enabled = False
 
 
 class FakeGiteaHandler(BaseHTTPRequestHandler):
@@ -62,6 +63,9 @@ class FakeGiteaHandler(BaseHTTPRequestHandler):
         if path != "/api/v1/repos/acme/mobile/issues":
             self._json(404, {"message": "not found"})
             return
+        if not self.server.issue_creation_enabled:
+            self._json(503, {"message": "release journey is still offline"})
+            return
         self.server.created_issues.append(payload)
         assignee = payload.get("assignee")
         self._json(

tests/e2e/test_mobile_offline_issue_release.py

@@ -219,6 +219,7 @@ def test_release_artifact_files_one_mobile_issue_exactly_once_after_offline_relo
 
             browser_errors.clear()  # Chromium reports expected network errors while the context is offline.
             failed_responses.clear()
+            fake.issue_creation_enabled = True
             context.set_offline(False)
             page.evaluate("window.dispatchEvent(new Event('online'))")
             for _ in range(80):