[8.x] Add restrictOnUpdate() method to the schema builder (#39350)

* Add restrictOnUpdate() method to the schema builder

Hi,

Laravel has a `cascadeOnUpdate()` but does not have a `restrictOnUpdate()`.

I know that i can use `onUpdate('restrict')` but since laravel already has a helper for the cascade and also has a restrict helper for the delete, it only makes sense to add helper for the restrict on update as well.

* Update ForeignKeyDefinition.php

Co-authored-by: Taylor Otwell <[email protected]>

Author: shadoWalker89

src/Illuminate/Database/Schema/ForeignKeyDefinition.php

@@ -24,6 +24,16 @@ public function cascadeOnUpdate()
         return $this->onUpdate('cascade');
     }
 
+    /**
+     * Indicate that updates should be restricted.
+     *
+     * @return $this
+     */
+    public function restrictOnUpdate()
+    {
+        return $this->onUpdate('restrict');
+    }
+
     /**
      * Indicate that deletes should cascade.
      *