Fixing fZlocalMinInds indexing

[ggenszler]

Describe your changes

Fixing fZ local minimum indexing in calcfZmin. Effects the Zodiacal Light prototype and Stark.

Type of change

• Bug fix (non-breaking change which fixes an issue)

Reference any relevant issues (don't forget the #)

Checklist before requesting a review

• [x] I have verified that all unit tests pass in a clean virtual environment and added new unit tests, as needed
• [x] I have run e2eTests and added new test scripts, as needed
• [x] I have verified that all docstrings are properly formatted and added new documentation, as needed