Update the Labs button's content and border colour (#25942)

GitOrigin-RevId: 36de10a13ff5d8721ffcac25c5c002fe25f7a125

services/web/frontend/stylesheets/bootstrap-5/abstracts/mixins.scss

@@ -62,9 +62,9 @@
 
 @mixin labs-button {
   @include ol-button-variant(
-    $color: var(--content-positive),
+    $color: var(--green-60),
     $background: var(--bg-accent-03),
-    $border: var(--green-40),
+    $border: var(--green-50),
     $hover-background: var(--bg-accent-03),
     $hover-border: var(--green-40),
     $borderless: false