switch to new attribute name

quadrat/block-template-parts/header.html

@@ -1,6 +1,6 @@
 <!-- wp:group {"tagName":"header","className":"site-header"} -->
 <header class="wp-block-group site-header"><!-- wp:site-title /-->
 
-<!-- wp:navigation {"isResponsive":true,"__unstable__location":"primary"} -->
+<!-- wp:navigation {"isResponsive":true,"__unstableLocation":"primary"} -->
 <!-- /wp:navigation --></header>
 <!-- /wp:group -->