Fixed a few minor issues with 'mpho' index template: removed 'theme' …

…attribute and re-leveraged existing 'no-results' pattern (#7571)

mpho/templates/index.html

@@ -1,4 +1,4 @@
-<!-- wp:template-part {"slug":"header","theme":"pub/mpho","area":"header"} /-->
+<!-- wp:template-part {"slug":"header","area":"header"} /-->
 
 <!-- wp:group {"style":{"border":{"left":{"width":"0px","style":"none"},"right":{"width":"0px","style":"none"},"top":{"width":"0px","style":"none"}},"spacing":{"padding":{"right":"5vw","left":"5vw"}}},"layout":{"type":"constrained"}} -->
 <div class="wp-block-group" style="border-top-style:none;border-top-width:0px;border-right-style:none;border-right-width:0px;border-left-style:none;border-left-width:0px;padding-right:5vw;padding-left:5vw"><!-- wp:group {"layout":{"type":"constrained"}} -->
@@ -24,9 +24,7 @@
 <!-- /wp:post-template -->
 
 <!-- wp:query-no-results -->
-<!-- wp:paragraph {"placeholder":"Add text or blocks that will display when a query returns no results."} -->
-<p>There are no posts yet.</p>
-<!-- /wp:paragraph -->
+<!-- wp:pattern {"slug":"mpho/no-results"} /-->
 <!-- /wp:query-no-results -->
 
 <!-- wp:query-pagination {"layout":{"type":"flex","justifyContent":"space-between"}} -->
@@ -44,4 +42,4 @@
 <!-- /wp:group --></div>
 <!-- /wp:group -->
 
-<!-- wp:template-part {"slug":"footer","theme":"pub/mpho","tagName":"footer"} /-->
+<!-- wp:template-part {"slug":"footer","tagName":"footer"} /-->