test(no-noninteractive-tabindex): promote peer-parity cases, drop audit file

Promoted one non-redundant case: article[tabindex={{0}}] as invalid, confirming
that mustache-number literals are resolved the same as string literals.

Author: johanrd

tests/audit/no-noninteractive-tabindex/peer-parity.js

@@ -134,6 +134,12 @@ ruleTester.run('template-no-noninteractive-tabindex', rule, {
       output: null,
       errors: [{ messageId: 'noNonInteractiveTabindex' }],
     },
+    // Mustache-number literal is resolved the same as the string form.
+    {
+      code: '<template><article tabindex={{0}}></article></template>',
+      output: null,
+      errors: [{ messageId: 'noNonInteractiveTabindex' }],
+    },
   ],
 });