feat(html): --quarto-border-radius follows Bootstrap's $enable-rounded

Author: gadenbuie

src/resources/formats/html/_quarto-rules.scss

@@ -587,7 +587,7 @@ div.ansi-escaped-output {
   --quarto-text-muted: #{$text-muted};
   --quarto-border-color: #{$table-border-color};
   --quarto-border-width: #{$border-width};
-  --quarto-border-radius: #{$border-radius};
+  --quarto-border-radius: #{if($enable-rounded == true, $border-rounded, 0)};
 }
 
 /* rules to support GT table styling */

src/resources/formats/html/bootstrap/_bootstrap-rules.scss

@@ -835,7 +835,7 @@ div.sourceCode {
   @if $code-block-bg {
     background-color: $code-block-bg-color;
     border: 1px solid $code-block-bg-color;
-    border-radius: $border-radius;
+    border-radius: var(--quarto-border-radius);
   } @else {
     background-color: $body-bg !important;
     border: none;