Disable animation for indicator on hidden elements (matrix-org#8340)

res/css/views/rooms/_EventTile.scss

@@ -694,6 +694,16 @@ $left-gutter: 64px;
     visibility: visible;
 }
 
+// Inverse of the above to *disable* the animation on any indicators. This approach
+// is less pretty, but is easier to target because otherwise we need to define the
+// animation for when it's shown which means duplicating the style definition in
+// multiple places.
+.mx_EventTile:not(:hover):not(.mx_EventTile_actionBarFocused):not([data-whatinput='keyboard'] :focus-within):not(.focus-visible:focus-within) {
+    .mx_MessageActionBar .mx_Indicator {
+        animation: none;
+    }
+}
+
 @media only screen and (max-width: 480px) {
 
     .mx_EventTile_line,