scss: get rid of the webkit audio rounded corner

- Gets rid of the webkit audio rounded corner, to harmonize the style
  across web browsers.

Co-Authored-by: iGor milhit <igor@milhit.ch>

assets/scss/_medias.scss

@@ -7,6 +7,11 @@
 
 @use "@picocss/pico/scss/colors/index" as *;
 
+/* To remove the rounded corner of the webkit audio player */
+audio::-webkit-media-controls-enclosure {
+    border-radius: 0;
+}
+
 .audio,
 .stream {
   border: var(--pico-border-width) solid $purple-200 ;