chore: add border style default to Example / Collapse button

Author: bolt-bot

packages/uikit-workshop/src/sass/scss/04-components/_pattern.scss

@@ -81,6 +81,7 @@
   font-family: $pl-font;
   border-color: #ddd;
   border-width: 1px; // fix for different browser defaults 
+  border-style: solid; // fix for different browser defaults (ex. Safari)
   display: flex;
   align-items: center;