fix(payments): avoid stale provider connections

tests/test_payment_http_client.py

@@ -0,0 +1,18 @@
+import unittest
+
+from bot.payment_providers.shared.http_client import HttpClientMixin
+
+
+class _DummyHttpClient(HttpClientMixin):
+    def __init__(self):
+        self._init_http_client(total_timeout=20)
+
+
+class PaymentHttpClientTests(unittest.IsolatedAsyncioTestCase):
+    async def test_http_client_does_not_reuse_provider_tcp_connections(self):
+        client = _DummyHttpClient()
+        try:
+            session = await client._get_session()
+            self.assertTrue(session.connector.force_close)
+        finally:
+            await client.close()