fix(2054): only calculate dropdown position when opening

Part-of: <https://dev.funkwhale.audio/funkwhale/funkwhale/-/merge_requests/2372>

front/src/components/audio/PlayButton.vue

@@ -105,6 +105,7 @@ const openMenu = () => {
   // little magic to ensure the menu is always visible in the viewport
   // By default, try to display it on the right if there is enough room
   const menu = dropdown.value.find('.menu')
+  if (!menu.classList.includes('visible')) {
     const viewportOffset = menu.get(0)?.getBoundingClientRect() ?? { right: 0, left: 0 }
     const viewportWidth = document.documentElement.clientWidth
     const rightOverflow = viewportOffset.right - viewportWidth
@@ -115,6 +116,7 @@ const openMenu = () => {
     } else if (leftOverflow > 0) {
       menu.css({ cssText: `right: -${leftOverflow + 5}px !important;` })
     }
+  }
 }
 </script>