WebUI: remove outdated CSS property

WebUI already has the standard counterparts.

src/webui/www/private/css/style.css

@@ -678,15 +678,11 @@ td.statusBarSeparator {
 }
 
 #searchResultsTableContainer {
-    -moz-height: calc(100% - 177px);
-    -webkit-height: calc(100% - 177px);
     height: calc(100% - 177px);
     overflow: auto;
 }
 
 #searchResultsTableDiv {
-    -moz-height: calc(100% - 26px) !important;
-    -webkit-height: calc(100% - 26px) !important;
     height: calc(100% - 26px) !important;
 }
 

src/webui/www/private/scripts/contextmenu.js

@@ -174,7 +174,6 @@ window.qBittorrent.ContextMenu ??= (() => {
         addTarget: function(t) {
             // prevent long press from selecting this text
             t.style.userSelect = "none";
-            t.style["-webkit-user-select"] = "none";
 
             this.targets[this.targets.length] = t;
             this.setupEventListeners(t);

src/webui/www/private/views/searchplugins.html

@@ -17,8 +17,6 @@
     #searchPluginsTable {
         width: 100%;
         height: calc(100% - 150px);
-        -moz-height: calc(100% - 150px);
-        -webkit-height: calc(100% - 150px);
     }
 
     #searchPluginsTable .dynamicTable {
@@ -27,8 +25,6 @@
 
     #searchPluginsTableDiv {
         height: calc(100% - 26px);
-        -moz-height: calc(100% - 26px);
-        -webkit-height: calc(100% - 26px);
     }
 
     #dynamicTableFixedHeaderDiv {