Blacklist border-radius property (use mixin instead) (#27900)

site/docs/4.2/assets/scss/_ads.scss

@@ -23,7 +23,7 @@
 
   @include media-breakpoint-up(sm) {
     max-width: 330px;
-    border-radius: 4px;
+    @include border-radius(4px);
   }
 }
 

site/docs/4.2/assets/scss/_brand.scss

@@ -10,7 +10,7 @@
   overflow: hidden;
   color: $bd-purple;
   background-color: #f9f9f9;
-  border-radius: .25rem;
+  @include border-radius;
 
   .inverse {
     color: $white;
@@ -79,7 +79,7 @@
   height: 4rem;
   margin-right: .25rem;
   margin-left: .25rem;
-  border-radius: .25rem;
+  @include border-radius;
 
   @include media-breakpoint-up(md) {
     width: 6rem;

site/docs/4.2/assets/scss/_callouts.scss

@@ -8,7 +8,7 @@
   margin-bottom: 1.25rem;
   border: 1px solid #eee;
   border-left-width: .25rem;
-  border-radius: .25rem;
+  @include border-radius;
 
   h4 {
     margin-top: 0;
@@ -20,7 +20,7 @@
   }
 
   code {
-    border-radius: .25rem;
+    @include border-radius;
   }
 
   + .bd-callout {

site/docs/4.2/assets/scss/_clipboard-js.scss

@@ -28,7 +28,7 @@
   cursor: pointer;
   background-color: transparent;
   border: 0;
-  border-radius: .25rem;
+  @include border-radius;
 
   &:hover {
     color: $white;

site/docs/4.2/assets/scss/_component-examples.scss

@@ -87,7 +87,7 @@
   height: 3rem;
   margin-bottom: .5rem;
   background-color: lighten($blue, 50%);
-  border-radius: .25rem;
+  @include border-radius;
 }
 
 .bd-example-container-sidebar {
@@ -95,14 +95,14 @@
   width: 4rem;
   height: 8rem;
   background-color: lighten($blue, 25%);
-  border-radius: .25rem;
+  @include border-radius;
 }
 
 .bd-example-container-body {
   height: 8rem;
   margin-right: 4.5rem;
   background-color: lighten($bd-purple, 25%);
-  border-radius: .25rem;
+  @include border-radius;
 }
 
 .bd-example-container-fluid {