fix: resolve CI linting and type checking issues

tests/test_cli.py

@@ -3,7 +3,6 @@
 import tempfile
 from pathlib import Path
 
-import pytest
 from click.testing import CliRunner
 
 from config_converter.cli import main
@@ -144,9 +143,6 @@ class TestCLI:
 
     def test_batch_command(self) -> None:
         """Test batch conversion command."""
-        import os
-        import tempfile
-
         with tempfile.TemporaryDirectory() as tmpdir:
             for i in range(3):
                 json_file = Path(tmpdir) / f"config{i}.json"