DukeCosmology/roman_imsim

AI Summary: This issue addresses a deprecation warning in GalSim where the `SED` method of `GSObjects` is deprecated since version 2.5. The task is to update all instances of `object.SED()` to `object.sed()` to use the new, lowercase method name. This is a direct code replacement to comply with the updated API.

AI Summary: Update the `pyproject.toml` file to include all necessary dependencies for the `wfirst_imsim` project. This involves reviewing the project's codebase to identify all imported packages and adding them to the `pyproject.toml` file's dependency list.