toolbar: drop no-box-shadow

This is now applied to all descendets of pb-toolbar so we don't need the
utility class.

src/index.scss

@@ -30,10 +30,6 @@ body {
     position: absolute;
 }
 
-.no-box-shadow {
-    box-shadow: unset !important;
-}
-
 // global style tweaks
 
 .#{$ns}-toast {

src/toolbar/Toolbar.tsx

@@ -22,7 +22,7 @@ const Toolbar: React.VFC = (_props) => {
         <div
             role="toolbar"
             onContextMenu={(e): void => e.preventDefault()}
-            className="pb-toolbar no-box-shadow"
+            className="pb-toolbar"
         >
             <ButtonGroup className="pb-toolbar-group pb-align-left">
                 <OpenButton id="open" />

src/toolbar/toolbar.scss

@@ -13,9 +13,12 @@
     z-index: $pt-z-index-content;
 }
 
+.pb-toolbar * {
+    box-shadow: unset !important;
+}
+
 .pb-toolbar-group {
     align-items: center;
-    display: flex;
     height: $pb-toolbar-height;
 
     &.pb-align-left {