TST: Relax rtol in modeling test
TST: Relax rtol in modeling test

Co-authored-by: William Jamieson <49bcc7198c513f154e9a5b6deb377cc6e411b6b0@stsci.edu>

saimn/astropy,mhvk/astropy,StuartLittlefair/astropy,astropy/astropy,pllim/astropy,mhvk/astropy,astropy/astropy,StuartLittlefair/astropy,StuartLittlefair/astropy,saimn/astropy,saimn/astropy,saimn/astropy,saimn/astropy,mhvk/astropy,pllim/astropy,astropy/astropy,lpsinger/astropy,astropy/astropy,StuartLittlefair/astropy,larrybradley/astropy,astropy/astropy,mhvk/astropy,lpsinger/astropy,pllim/astropy,StuartLittlefair/astropy,larrybradley/astropy,lpsinger/astropy,lpsinger/astropy,pllim/astropy,lpsinger/astropy,larrybradley/astropy,larrybradley/astropy,mhvk/astropy,larrybradley/astropy,pllim/astropy