test: Skip SSL tests when not using external containers

SSL tests require docker-compose with datajoint/mysql image which has
SSL certificates configured. Testcontainers uses the official mysql
image which doesn't have SSL set up.

Tests marked with @requires_ssl will skip unless DJ_USE_EXTERNAL_CONTAINERS
is set, allowing CI to pass while still enabling SSL tests when running
with docker-compose locally.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: dimitri-yatsenko

tests/integration/test_tls.py

@@ -1,17 +1,27 @@
 import logging
+import os
 
 import pytest
 from pymysql.err import OperationalError
 
 import datajoint as dj
 
+# SSL tests require docker-compose with datajoint/mysql image (has SSL configured)
+# Testcontainers with official mysql image doesn't have SSL certificates
+requires_ssl = pytest.mark.skipif(
+    os.environ.get("DJ_USE_EXTERNAL_CONTAINERS", "").lower() not in ("1", "true", "yes"),
+    reason="SSL tests require external containers (docker-compose) with SSL configured",
+)
 
+
+@requires_ssl
 def test_explicit_ssl_connection(db_creds_test, connection_test):
     """When use_tls=True is specified, SSL must be active."""
     result = dj.conn(use_tls=True, reset=True, **db_creds_test).query("SHOW STATUS LIKE 'Ssl_cipher';").fetchone()[1]
     assert len(result) > 0, "SSL should be active when use_tls=True"
 
 
+@requires_ssl
 def test_ssl_auto_detect(db_creds_test, connection_test, caplog):
     """When use_tls is not specified, SSL is preferred but fallback is allowed with warning."""
     with caplog.at_level(logging.WARNING):
@@ -33,6 +43,7 @@ def test_insecure_connection(db_creds_test, connection_test):
     assert result == ""
 
 
+@requires_ssl
 def test_reject_insecure(db_creds_test, connection_test):
     """Users with REQUIRE SSL cannot connect without SSL."""
     with pytest.raises(OperationalError):