mark test_comments as xfail on pypy
mark test_comments as xfail on pypy

while migrating this code it was noticed that this test was failing even
on the original py repository, so it was decided to xfail it and investigate
later

hackebrot/pytest,lukas-bednar/pytest,markshao/pytest,ropez/pytest,skylarjhdownes/pytest,Akasurde/pytest,Bachmann1234/pytest,The-Compiler/pytest,userzimmermann/pytest,nicoddemus/pytest,MichaelAquilina/pytest,userzimmermann/pytest,pfctdayelise/pytest,vodik/pytest,txomon/pytest,vodik/pytest,hpk42/pytest,tomviner/pytest,RonnyPfannschmidt/pytest,malinoff/pytest,tareqalayan/pytest,tgoodlet/pytest,alfredodeza/pytest,pytest-dev/pytest,MengJueM/pytest,JonathonSonesen/pytest,etataurov/pytest,vmalloc/dessert,jaraco/pytest,omarkohl/pytest,davidszotten/pytest,nicoddemus/pytest,tomviner/pytest,ddboline/pytest,Bachmann1234/pytest,MengJueM/pytest,rmfitzpatrick/pytest,hpk42/pytest,flub/pytest,omarkohl/pytest,lukas-bednar/pytest,eli-b/pytest,The-Compiler/pytest,ropez/pytest,JonathonSonesen/pytest