“Murder on the Dancefloor” — a disco delight by British singer Sophie Ellis-Bextor — was released in 2001, it became a bit hit in the UK. But the track from her debut album, “Read My Lips,” failed to slay the States.Twenty-three years and one full-frontal nude dancing scene later, all that has changed because of “Saltburn.”The euphoric victory boogie by Barry Keoghan’s coked-up character Oliver at the end of the buzzy black comedy psychological thriller is set to the bass-bumping groove of “Murder on the Dancefloor.”And after “Saltburn” went from its limited theatrical release in November to its streaming debut on Amazon Prime Video on Dec.