Remove existing Sass for backlink

app/assets/stylesheets/components/vendor/govuk-back-link.scss

@@ -1,53 +0,0 @@
-.govuk-back-link {
-
-  @include core-16;
-  color: $text-colour;
-  display: inline-block;
-  position: relative;
-  margin-top: $gutter-half;
-  margin-bottom: $gutter / 3;
-  padding-left: $gutter-half - 1px;
-  border-bottom: 1px solid $text-colour;
-  text-decoration: none;
-
-  &:link,
-  &:visited {
-    color: $text-colour;
-  }
-
-  &:before {
-    display: block;
-    width: 0;
-    height: 0;
-    border-style: solid;
-    border-color: transparent;
-    -webkit-clip-path: polygon(0% 50%, 100% 100%, 100% 0%);
-    clip-path: polygon(0% 50%, 100% 100%, 100% 0%);
-    border-width: 5px 6px 5px 0;
-    border-right-color: inherit;
-    content: "";
-    position: absolute;
-    top: -1px;
-    bottom: 1px;
-    left: 0;
-    margin: auto;
-  }
-
-  &:after {
-    content: "";
-    position: absolute;
-    top: -$gutter-half;
-    left: -3px;
-    width: 100%;
-    height: 100%;
-    border-style: solid;
-    border-width: $gutter-half $gutter $gutter-half 3px;
-    border-color: transparent;
-  }
-
-  &:focus {
-    &:after {
-      border-color: $yellow
-    }
-  }
-}