test(@angular/cli): add update test from version 12 to 13

This is needed as updating multiple major versions of `@angular/cli`  and `@angular/core` at once is not supported therefore an update from 12 to 14 will fail.

Author: alan-agius4

tests/legacy-cli/e2e/tests/update/update-9.ts

@@ -25,6 +25,9 @@ export default async function () {
 
     // Update Angular to 12
     await ng('update', '@angular/cli@12', '@angular/core@12');
+
+    // Update Angular to 13
+    await ng('update', '@angular/cli@13', '@angular/core@13');
   } finally {
     await setRegistry(true);
   }