refactor(test): ensure env cleanup with try-finally block

Applied Gemini Code Assist suggestion to wrap test logic in try-finally,
preventing env var leak if test fails. This improves test isolation and
prevents flaky tests from state pollution.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: weiguangli-io

tests/unittests/cli/utils/test_cli_deploy.py

@@ -670,10 +670,11 @@ def test_loads_dotenv_before_import(self, tmp_path: Path) -> None:
     )
     (tmp_path / ".env").write_text("_ADK_TEST_DEPLOY_VAR=from_dotenv\n")
 
-    # Should not raise because .env is loaded before import
-    cli_deploy._validate_agent_import(
-        str(tmp_path), "root_agent", is_config_agent=False
-    )
-
-    # Clean up the env var
-    os.environ.pop("_ADK_TEST_DEPLOY_VAR", None)
+    try:
+        # Should not raise because .env is loaded before import
+        cli_deploy._validate_agent_import(
+            str(tmp_path), "root_agent", is_config_agent=False
+        )
+    finally:
+        # Clean up the env var
+        os.environ.pop("_ADK_TEST_DEPLOY_VAR", None)