fix(material/select): add aria-hidden to select value

Author: andrewseguin

src/material/select/select.html

@@ -4,7 +4,7 @@
      #fallbackOverlayOrigin="cdkOverlayOrigin"
      #trigger>
 
-  <div class="mat-mdc-select-value" [attr.id]="_valueId">
+  <div class="mat-mdc-select-value" [attr.id]="_valueId" aria-hidden="true">
     @if (empty) {
       <span class="mat-mdc-select-placeholder mat-mdc-select-min-line">{{placeholder}}</span>
     } @else {