openexr: add conflicts/replaces with ilmbase
openexr: add conflicts/replaces with ilmbase

ilmbase no longer exists and should be removed when openexr was installed before.
See https://github.com/msys2/MINGW-packages/pull/12871#issuecomment-1235816186

stahta01/MINGW-packages,oscarfv/MINGW-packages,lhmouse/MINGW-packages,JPeterMugaas/MINGW-packages,oscarfv/MINGW-packages,JPeterMugaas/MINGW-packages,lhmouse/MINGW-packages,lhmouse/MINGW-packages,stahta01/MINGW-packages,oscarfv/MINGW-packages,JPeterMugaas/MINGW-packages,JPeterMugaas/MINGW-packages,JPeterMugaas/MINGW-packages,stahta01/MINGW-packages,lhmouse/MINGW-packages,stahta01/MINGW-packages,JPeterMugaas/MINGW-packages,stahta01/MINGW-packages,lhmouse/MINGW-packages,oscarfv/MINGW-packages,oscarfv/MINGW-packages,oscarfv/MINGW-packages,lhmouse/MINGW-packages,stahta01/MINGW-packages