Update binary lens caustic class for MuLensModel 3.4.0

[Copilot]

MulensModel 3.4.0 renamed the binary caustic helper used in the AAS Session C notebook, breaking the binary lens exercises that call the old Caustics class.

• Notebook adjustment: In Session C “Fitting_Binary_Lenses”, replace the deprecated mm.Caustics with mm.CausticsBinary for both the interactive slider plot and the example magnification/trajectory plot so the notebook runs against MuLensModel 3.4.0.

Example update:

# Binary lens caustic and critical curves
binary_caustic = mm.CausticsBinary(s=s, q=q)
bx, by = binary_caustic.get_caustics()

Original prompt

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This section details on the original issue you should resolve

<issue_title>Conflicting Versions of MuLensModel</issue_title>
<issue_description>I noticed MuLensModel version 3.4.0 is required in the env.yml. I think this adds a conflict with the AAS session C notebook on binary lenses. The notebook calls the Caustics class, see for example Exercise 1. In version 3.4.0, the Caustics class was refactored to CausticsBinary. A simple refactoring fixes this. </issue_description>

<agent_instructions>Only edit the notebooks in AAS_Workshop or Extras. Other versions are automation artifacts.</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes Conflicting Versions of MuLensModel #33

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