[SPARK-55600][PYTHON] Fix pandas to arrow loses row count when schema has 0 columns on classic

[Yicong-Huang]

What changes were proposed in this pull request?

This PR fixes the row count loss issue when creating a Spark DataFrame from a pandas DataFrame with 0 columns in classic.

The issue occurs due to PyArrow limitations when creating RecordBatches or Tables with 0 columns - row count information is lost.

Why are the changes needed?

Before this fix:

import pandas as pd
from pyspark.sql.types import StructType

pdf = pd.DataFrame(index=range(5))  # 5 rows, 0 columns
df = spark.createDataFrame(pdf, schema=StructType([]))
df.count()  # Returns 0 (wrong!)

After this fix:

df.count()  # Returns 5 (correct!)

Does this PR introduce any user-facing change?

Yes. Creating a DataFrame from a pandas DataFrame with 0 columns now correctly preserves the row count in Classic Spark.

How was this patch tested?

Added unit test test_from_pandas_dataframe_with_zero_columns in test_creation.py that tests both Arrow-enabled and Arrow-disabled paths.

Was this patch authored or co-authored using generative AI tooling?

No