🏗 Execute each visual diff test in a separate subdomain (#20671)
🏗 Execute each visual diff test in a separate subdomain (#20671)

* Execute each visual diff test in a separate subdomain

* Added comment explaining the localhost redirection behavior

erwinmombay/amphtml,sharethrough/amphtml,laterpay/amphtml,mhc-gh/amphtml,techhtml/amphtml,cvializ/amphtml,mhc-gh/amphtml,prateekbh/amphtml,laterpay/amphtml,widespace-os/amphtml,nexxtv/amphtml,jridgewell/amphtml,honeybadgerdontcare/amphtml,src-code/amphtml,taboola/amphtml,dotandads/amphtml,media-net/amphtml,Gregable/amphtml,jpettitt/amphtml,jridgewell/amphtml,voyagegroup/amphtml,zhouyx/amphtml,lannka/amphtml,jpettitt/amphtml,taboola/amphtml,tlong2/amphtml,alanorozco/amphtml,jridgewell/amphtml,laterpay/amphtml,taboola/amphtml,lannka/amphtml,jmadler/amphtml,jmadler/amphtml,smartadserver/amphtml,cvializ/amphtml,rsimha-amp/amphtml,techhtml/amphtml,alanorozco/amphtml,honeybadgerdontcare/amphtml,honeybadgerdontcare/amphtml,rsimha-amp/amphtml,voyagegroup/amphtml,media-net/amphtml,nexxtv/amphtml,taboola/amphtml,media-net/amphtml,laterpay/amphtml,jpettitt/amphtml,jmadler/amphtml,zhouyx/amphtml,lannka/amphtml,rsimha-amp/amphtml,erwinmombay/amphtml,ampproject/amphtml,alanorozco/amphtml,adup-tech/amphtml,sebastianbenz/amphtml,jridgewell/amphtml,sharethrough/amphtml,jridgewell/amphtml,rsimha-amp/amphtml,rsimha-amp/amphtml,honeybadgerdontcare/amphtml,honeybadgerdontcare/amphtml,prateekbh/amphtml,jridgewell/amphtml,yandex-pcode/amphtml,cvializ/amphtml,erwinmombay/amphtml,danielrozenberg/amphtml,sebastianbenz/amphtml,nexxtv/amphtml,danielrozenberg/amphtml,smartadserver/amphtml,erwinmombay/amphtml,voyagegroup/amphtml,src-code/amphtml,src-code/amphtml,cory-work/amphtml,media-net/amphtml,ampproject/amphtml,widespace-os/amphtml,cvializ/amphtml,zhouyx/amphtml,tlong2/amphtml,jpettitt/amphtml,smartadserver/amphtml,taboola/amphtml,nexxtv/amphtml,yandex-pcode/amphtml,prateekbh/amphtml,alanorozco/amphtml,dotandads/amphtml,laterpay/amphtml,lannka/amphtml,techhtml/amphtml,sharethrough/amphtml,Gregable/amphtml,adup-tech/amphtml,media-net/amphtml,mhc-gh/amphtml,prateekbh/amphtml,danielrozenberg/amphtml,tlong2/amphtml,danielrozenberg/amphtml,honeybadgerdontcare/amphtml,danielrozenberg/amphtml,adup-tech/amphtml,zhangsu/amphtml,mhc-gh/amphtml,tlong2/amphtml,voyagegroup/amphtml,sebastianbenz/amphtml,adup-tech/amphtml,alanorozco/amphtml,ampproject/amphtml,zhangsu/amphtml,dotandads/amphtml,zhouyx/amphtml,jmadler/amphtml,danielrozenberg/amphtml,ampproject/amphtml,Gregable/amphtml,sebastianbenz/amphtml,mhc-gh/amphtml,erwinmombay/amphtml,rsimha-amp/amphtml,tlong2/amphtml,cvializ/amphtml,erwinmombay/amphtml,media-net/amphtml,sharethrough/amphtml,cory-work/amphtml,tlong2/amphtml,zhouyx/amphtml,yandex-pcode/amphtml,adup-tech/amphtml,nexxtv/amphtml,zhangsu/amphtml,taboola/amphtml,cory-work/amphtml,nexxtv/amphtml,lannka/amphtml,yandex-pcode/amphtml,src-code/amphtml,dotandads/amphtml,yandex-pcode/amphtml,src-code/amphtml,widespace-os/amphtml,nexxtv/amphtml,sharethrough/amphtml,prateekbh/amphtml,sebastianbenz/amphtml,jpettitt/amphtml,jpettitt/amphtml,techhtml/amphtml,media-net/amphtml,mhc-gh/amphtml,jpettitt/amphtml,cory-work/amphtml,sebastianbenz/amphtml,jridgewell/amphtml,prateekbh/amphtml,Gregable/amphtml,cory-work/amphtml,widespace-os/amphtml,widespace-os/amphtml,voyagegroup/amphtml,jmadler/amphtml,danielrozenberg/amphtml,adup-tech/amphtml,mhc-gh/amphtml,prateekbh/amphtml,smartadserver/amphtml,lannka/amphtml,ampproject/amphtml,jmadler/amphtml,alanorozco/amphtml,smartadserver/amphtml,alanorozco/amphtml,sharethrough/amphtml,zhouyx/amphtml,alanorozco/amphtml,yandex-pcode/amphtml,voyagegroup/amphtml,cory-work/amphtml,Gregable/amphtml,jpettitt/amphtml,ampproject/amphtml,ampproject/amphtml,techhtml/amphtml,zhangsu/amphtml,dotandads/amphtml,widespace-os/amphtml,taboola/amphtml,Gregable/amphtml,zhouyx/amphtml,voyagegroup/amphtml,techhtml/amphtml,ampproject/amphtml,danielrozenberg/amphtml,yandex-pcode/amphtml,laterpay/amphtml,Gregable/amphtml,cory-work/amphtml,zhangsu/amphtml,Gregable/amphtml,dotandads/amphtml,src-code/amphtml,cvializ/amphtml,honeybadgerdontcare/amphtml,lannka/amphtml,rsimha-amp/amphtml,zhangsu/amphtml,mhc-gh/amphtml,media-net/amphtml,smartadserver/amphtml