fix: Cleanup's _validate_job_dir/build_*_cleanup_command hardcoded the

[singlaamitesh]

Fixes #69813

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Cleanup's validate_job_dir/build*_cleanup_command hardcoded the default base dir, so any custom remote_base_dir (validated more loosely at init) always failed cleanup at job completion; they now accept the operator's actual configured base_dir, and a changelog entry documenting the fix was added to providers/ssh/docs/changelog.rst.

How this was tested: airflow dags test

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