SIENTIAPDE-1445

Refactor imports and enhance timestamp handling in API and test files

- Removed redundant import statements in api.py and prepare_worker.py for cleaner code.
- Updated timestamp format in test cases to include timezone information for consistency.
- Adjusted test configurations to align with new API structure for improved accuracy in data handling.

tests/utils/test_connectors_config.py

@@ -173,9 +173,9 @@ def test_build_api_config_with_env_vars():
     with patch.dict(
         os.environ,
         {
-            'API_BASE_URL': 'https://api.production.com',
-            'API_AUTH_TYPE': 'bearer',
-            'API_AUTH_TOKEN': 'secret_token_123',
+            'PI_WEB_API_BASE_URL': 'https://api.production.com',
+            'PI_WEB_API_AUTH_TYPE': 'bearer',
+            'PI_WEB_API_AUTH_TOKEN': 'secret_token_123',
         },
     ):
         config = build_api_config()