fix lsst error model import path

[ztq1996]

There is no LSST_error_model in rail_astro_tools anymore, therefore, all reference to that needs to be fixed

Code Quality

• [ ] My code follows the code style of this project
• [ ] I have written unit tests or justified all instances of #pragma: no cover; in the case of a bugfix, a new test that breaks as a result of the bug has been added
• [ ] My code contains relevant comments and necessary documentation for future maintainers; the change is reflected in applicable demos/tutorials (with output cleared!) and added/updated docstrings use the NumPy docstring format
• [ ] Any breaking changes, described above, are accompanied by backwards compatibility and deprecation warnings

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 100.00%. Comparing base (c22b723) to head (5eba13e).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #157 +/- ## ========================================= Coverage 100.00% 100.00% ========================================= Files 1 1 Lines 1 1 ========================================= Hits 1 1 ```

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