BUG: series with tuple name has a column multiindex in internal pandas frame

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Reproducible Example

import modin.pandas as pd

series = pd.Series([1, 2, 3], name=(3, 'a'))
assert series._query_compiler._modin_frame.to_pandas().columns.nlevels == 1

Issue Description

series._query_compiler._modin_frame should have a single-level column index.

Expected Behavior

series._query_compiler._modin_frame should have a single-level column index.

Error Logs

N/A

Installed Versions

INSTALLED VERSIONS

commit : 99037af07717cba5a53155595ad28202e59aba90 python : 3.9.21 python-bits : 64 OS : Darwin OS-release : 24.6.0 Version : Darwin Kernel Version 24.6.0: Mon Aug 11 21:16:34 PDT 2025; root:xnu-11417.140.69.701.11~1/RELEASE_ARM64_T6020 machine : arm64 processor : arm byteorder : little LC_ALL : None LANG : en_US.UTF-8 LOCALE : en_US.UTF-8

Modin dependencies

modin : 0.37.0+2.g99037af0 ray : 2.44.1 dask : 2024.8.0 distributed : 2024.8.0

pandas dependencies

pandas : 2.2.3 numpy : 2.0.2 pytz : 2025.2 dateutil : 2.9.0.post0 pip : 24.2 Cython : None sphinx : 7.4.7 IPython : 8.18.1 adbc-driver-postgresql: None adbc-driver-sqlite : None bs4 : 4.13.4 blosc : None bottleneck : None dataframe-api-compat : None fastparquet : 2024.11.0 fsspec : 2025.3.2 html5lib : None hypothesis : None gcsfs : None jinja2 : 3.1.6 lxml.etree : 5.3.2 matplotlib : 3.9.4 numba : None numexpr : 2.10.2 odfpy : None openpyxl : 3.1.5 pandas_gbq : 0.28.0 psycopg2 : 2.9.10 pymysql : None pyarrow : 18.1.0 pyreadstat : None pytest : 8.4.0 python-calamine : None pyxlsb : None s3fs : 2025.3.2 scipy : 1.13.1 sqlalchemy : 2.0.40 tables : N/A tabulate : 0.9.0 xarray : 2024.7.0 xlrd : 2.0.1 xlsxwriter : None zstandard : None tzdata : 2025.2 qtpy : None pyqt5 : None