docs: add missing data-bs-theme="light" in navbars color schemes markup (#40504)

Author: julien-deramond

site/content/docs/5.3/components/navbar.md

@@ -428,7 +428,7 @@ Navbar themes are easier than ever thanks to Bootstrap's combination of Sass and
   <!-- Navbar content -->
 </nav>
 
-<nav class="navbar" style="background-color: #e3f2fd;">
+<nav class="navbar" style="background-color: #e3f2fd;" data-bs-theme="light">
   <!-- Navbar content -->
 </nav>
 ```