Update requirements.txt

Now that SU 2.0 is out we can remove the dev version install

Author: bjkuhn

notebooks/WFC3/slitlessutils_UVIS_subarray_extraction/requirements.txt

@@ -4,4 +4,4 @@ jupyter
 jupyterlab==4.3.1
 matplotlib==3.9.4
 pyregion
-git+https://github.com/spacetelescope/slitlessutils.git
+slitlessutils>=2.0