[SPARK-56634][PYTHON][TESTS] Add __main__ block to pyspark.sql.tests.connect.test_session

[zhengruifeng]

What changes were proposed in this pull request?

Adds the standard if __name__ == "__main__" block to python/pyspark/sql/tests/connect/test_session.py, matching the convention used by every other test_*.py module in the same directory (e.g., test_connect_basic.py):

if __name__ == "__main__":
    from pyspark.testing import main

    main()

Why are the changes needed?

Without the block, this file cannot be invoked directly via python python/pyspark/sql/tests/connect/test_session.py, unlike its siblings. It is the only test_*.py file under python/pyspark/**/tests/ missing this block.

Does this PR introduce any user-facing change?

No.

How was this patch tested?

Pure addition; the appended block is byte-identical to the pattern used by sibling files such as test_connect_basic.py. Verified the module still parses with python -c "import ast; ast.parse(open('python/pyspark/sql/tests/connect/test_session.py').read())".

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

Generated-by: Claude Code (claude-opus-4-7)

[zhengruifeng]

it seems the test itself cannot pass, mark a draft first