feat(sales): validate PDF timezone parameter

app/Domains/Sale/Requests/AdminAppSaleModificationPdfRequest.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace App\Domains\Sale\Requests;
+
+use App\Domains\Shared\Rules\ValidTimezone;
+use Illuminate\Foundation\Http\FormRequest;
+
+class AdminAppSaleModificationPdfRequest extends FormRequest
+{
+    public function authorize(): bool
+    {
+        return true;
+    }
+
+    /** @return array<string, list<string>> */
+    public function rules(): array
+    {
+        return [
+            'timezone' => ['required', 'string', new ValidTimezone],
+        ];
+    }
+}