Move converter test to test_io.py

Add test_converters_partial() to test_io.py for read_excel converters

Author: Sachi-Parashar

tests/test_io.py

@@ -1792,3 +1792,13 @@ def test_read_json_engine() -> None:
         pd.read_json(dd, lines=False, engine="pyarrow")  # type: ignore[call-overload] # pyright: ignore[reportArgumentType, reportCallIssue]
         pd.read_json(io.StringIO(data), engine="pyarrow")  # type: ignore[call-overload] # pyright: ignore[reportArgumentType]
         pd.read_json(io.StringIO(data), lines=True, engine="pyarrow")  # type: ignore[call-overload] # pyright: ignore[reportArgumentType, reportCallIssue]
+
+
+def test_converters_partial() -> None:
+    from functools import partial
+    import pandas as pd
+    from typing_extensions import assert_type
+
+    partial_func = partial(pd.to_datetime, errors="coerce")
+    df = pd.read_excel("foo.xlsx", converters={"field_1": partial_func})
+    assert_type(df, pd.DataFrame)