Add tests for write table concurrency

[timsaucer]

This adds unit testing for write tables APIs to test concurrency.

[Copilot]

Pull Request Overview

This PR adds concurrency testing for the write_table API by introducing a parameterized test that validates concurrent write operations with multiple threads.

• Adds a new test test_concurrent_write_tables that uses threading to test concurrent writes
• Changes the table_filepath fixture scope from "module" to "function" to ensure test isolation

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
rerun_py/tests/e2e_redap_tests/test_table_write.py	Adds concurrent write test with threading support
rerun_py/tests/e2e_redap_tests/conftest.py	Changes fixture scope to function-level for better test isolation

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[ntjohnson1]

Test looks reasonable to me as long as we assume write_table releases the GIL. The test doesn't ensure that the threads run concurrently. If the threads run sequentially this would still pass IIUC.

Approving if that is the desired scope, aince releasing the GIL should be supported by work in datafusion-python (that we both touched parts of).