Add type hints to test functions in test_percent_patterns

Added type hints for function signatures and improved code clarity.

Author: SergioGarcia00

pandas/tests/io/sql/test_percent_patterns.py

@@ -1,27 +1,30 @@
 # pandas/tests/io/sql/test_percent_patterns.py
 import os
-
 import pytest
+from typing import TYPE_CHECKING
 
 sa = pytest.importorskip("sqlalchemy")
 
+if TYPE_CHECKING:
+    from sqlalchemy.engine import Engine
+
 PG = os.environ.get("PANDAS_TEST_POSTGRES_URI")
 URL = PG or "sqlite+pysqlite:///:memory:"
 
 
-def _eng():
+def _eng() -> "Engine":
     return sa.create_engine(URL)
 
 
-def test_text_modulo():
+def test_text_modulo() -> None:
     import pandas as pd
 
     with _eng().connect() as c:
         df = pd.read_sql(sa.text("SELECT 5 % 2 AS r"), c)
     assert df.iloc[0, 0] == 1
 
 
-def test_like_single_percent():
+def test_like_single_percent() -> None:
     import pandas as pd
 
     with _eng().connect() as c:
@@ -32,7 +35,7 @@ def test_like_single_percent():
     assert len(df) == 1
 
 
-def test_sqlalchemy_expr_percent_operator():
+def test_sqlalchemy_expr_percent_operator() -> None:
     from sqlalchemy import (
         literal,
         select,