Remove ButtonResetDefault from mx_AccessibleButton of EventTile_keyRequestInfo_text (#8678)

To respect the concept of cascading. Also using a mixin to unset the declarations can easily cause a style inconsistency.

Signed-off-by: Suguru Hirahara <luixxiul@users.noreply.github.com>

res/css/views/rooms/_EventTile.scss

@@ -638,10 +638,12 @@ $threadInfoLineHeight: calc(2 * $font-12px); // See: _commons.scss
         opacity: 0.5;
 
         .mx_AccessibleButton {
-            @mixin ButtonResetDefault;
             color: $primary-content;
             text-decoration: underline;
-            cursor: pointer;
+
+            &.mx_AccessibleButton_kind_link_inline {
+                padding: 0;
+            }
         }
     }
 }