fix: remove unused mock imports to pass ruff linter

`call` and `patch` were imported but never referenced in the test file,
causing the Ruff F401 check to fail in CI.

Author: Jaypatel1511

tests/test_get_history_metadata.py

@@ -11,7 +11,7 @@
      YFPricesMissingError instead of returning the metadata already cached.
 """
 import unittest
-from unittest.mock import MagicMock, call, patch
+from unittest.mock import MagicMock
 
 from yfinance.scrapers.history import PriceHistory
 from yfinance.exceptions import YFPricesMissingError