It’s almost become a model in recent years: If a song’s a hit, the copyright-infringement lawsuits follow, and Dua Lipa was clobbered with two of them in four days last week. Her global hit “Levitating,” which has spent 68 weeks on the Billboard Hot 100, has drawn two lawsuits from songwriters claiming the song infringes on their compositions, according to multiple media reports. The first was filed March 1 by a Florida reggae group called Artikal Sound System, claiming that Lipa’s song lifts fr