Cherry pick Bootstrap fix after 5.3.0-alpha2

See f77117141d.

paige/README.md

@@ -0,0 +1 @@
+`node_modules/bootstrap` was manually modified to apply a [critical fix](https://github.com/twbs/bootstrap/commit/f77117141dfe34d8fe984eabddf660e29cb96a57) that came after 5.3.0-alpha2.

paige/node_modules/bootstrap/scss/_carousel.scss

@@ -230,9 +230,15 @@
 
 @if $enable-dark-mode {
   @include color-mode(dark) {
+    @if $color-mode-type == "media-query" {
+      .carousel {
+        @include carousel-dark();
+      }
+    } @else {
       .carousel,
       &.carousel {
         @include carousel-dark();
       }
     }
   }
+}