Resolve generated kick_off.py paths relative to script directory

[gordonwatts]

Motivation

• Ensure generated kick_off.py scripts resolve the capabilities file and transformer command relative to the script file itself so the generated runner works when executed from another working directory or after being copied.
• Fix remaining hardcoded /generated/... references that were missed by the previous WSL script fix.

Description

• Updated the default kick_off.py template in servicex_local/science_images.py to compute script_dir from __file__, load transformer_capabilities.json from script_dir, and normalize info["command"] so /generated/... and relative paths become script-relative while leaving other absolute paths unchanged.
• Applied the same script_dir + command-normalization logic to the WSL kick_off.py template embedded in WSL2ScienceImage.transform so the WSL-generated runner also resolves paths correctly.
• Changed the generated WSL wrapper to invoke python "$script_dir/kick_off.py" instead of referring to the old generated-directory path.
• Removed the now-unused wsl_generated_files_dir local variable in WSL2ScienceImage.transform after switching to script-relative resolution.

Testing

• Ran python -m black --check servicex_local/science_images.py, which passed.
• Ran python -m flake8 servicex_local/science_images.py, which failed due to existing E501 line-length violations in the file and not caused by these changes.
• Ran pytest, which failed with pre-existing TransformStatus validation errors in adaptor/deliver tests and are unrelated to the kick_off.py path fixes.

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Codex Task