[Glitch] Accessibility: Mark pseudo element content in link footer as decorative

Port 9fe97e1ad6 to glitch-soc

Signed-off-by: Claire <claire.github-309c@sitedethib.com>

app/javascript/flavours/glitch/features/ui/components/link_footer.module.scss

@@ -41,6 +41,10 @@
 
     &:not(:last-child)::after {
       content: ' · ';
+
+      @supports (content: 'x' / 'y') {
+        content: ' · ' / '';
+      }
     }
   }