Remove scrollbar styles and related conditions from head.html

- Deprecates var `site.Params.assets.disableScrollBarStyle`

assets/css/includes/scroll-bar.css

@@ -1,59 +0,0 @@
-/* from reset */
-::-webkit-scrollbar-track {
-    background: 0 0;
-}
-
-::-webkit-scrollbar-thumb {
-    background: var(--tertiary);
-    border: 5px solid var(--theme);
-    border-radius: var(--radius);
-}
-
-[data-theme="light"] .list::-webkit-scrollbar-thumb {
-    border: 5px solid var(--code-bg);
-}
-
-::-webkit-scrollbar-thumb:hover {
-    background: var(--secondary);
-}
-
-::-webkit-scrollbar:not(.highlighttable, .highlight table, .gist .highlight) {
-    background: var(--theme);
-}
-
-/* from post-single */
-.md-content .highlighttable td .highlight pre code::-webkit-scrollbar {
-    display: none;
-}
-
-.md-content :not(table) ::-webkit-scrollbar-thumb {
-    border: 2px solid var(--code-block-bg);
-    background: rgb(113, 113, 117);
-}
-
-.md-content :not(table) ::-webkit-scrollbar-thumb:hover {
-    background: rgb(163, 163, 165);
-}
-
-.gist table::-webkit-scrollbar-thumb {
-    border: 2px solid rgb(255, 255, 255);
-    background: rgb(173, 173, 173);
-}
-
-.gist table::-webkit-scrollbar-thumb:hover {
-    background: rgb(112, 112, 112);
-}
-
-.md-content table::-webkit-scrollbar-thumb {
-    border-width: 2px;
-}
-
-/* from zmedia */
-@media screen and (min-width: 768px) {
-
-    /* reset */
-    ::-webkit-scrollbar {
-        width: 19px;
-        height: 11px;
-    }
-}

layouts/partials/head.html

@@ -42,11 +42,6 @@
 {{- $includes := slice }}
 {{- $includes = $includes | append (" " | resources.FromString "assets/css/includes-blank.css")}}
 
-{{- if not (eq site.Params.assets.disableScrollBarStyle true) }}
-    {{- $ScrollStyle := (resources.Get "css/includes/scroll-bar.css") }}
-    {{- $includes = (append $ScrollStyle $includes) }}
-{{- end }}
-
 {{- $includes_all := $includes | resources.Concat "assets/css/includes.css" }}
 
 {{- $theme_vars := (resources.Get "css/core/theme-vars.css") }}
@@ -139,12 +134,6 @@
             }
         }
 
-        @media (prefers-color-scheme: light) {
-            .list::-webkit-scrollbar-thumb {
-                border-color: var(--code-bg);
-            }
-        }
-
     </style>
     {{- end }}
 </noscript>