chore: upgrade to L9

BREAKING CHANGE: This commit updates the Laravel framework to version 9. Additionally, it also updates outdated and abandoned dependencies in the composer.json file.

The resources/lang directory has also been moved to the repository's root directory.

lang/en/pagination.php

@@ -0,0 +1,38 @@
+<?php
+
+/*
+ * Copyright © 2020 Miguel Nogueira
+ *
+ *   This file is part of Raspberry Staff Manager.
+ *
+ *     Raspberry Staff Manager is free software: you can redistribute it and/or modify
+ *     it under the terms of the GNU General Public License as published by
+ *     the Free Software Foundation, either version 3 of the License, or
+ *     (at your option) any later version.
+ *
+ *     Raspberry Staff Manager is distributed in the hope that it will be useful,
+ *     but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *     GNU General Public License for more details.
+ *
+ *     You should have received a copy of the GNU General Public License
+ *     along with Raspberry Staff Manager.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+return [
+
+    /*
+    |--------------------------------------------------------------------------
+    | Pagination Language Lines
+    |--------------------------------------------------------------------------
+    |
+    | The following language lines are used by the paginator library to build
+    | the simple pagination links. You are free to change them to anything
+    | you want to customize your views to better match your application.
+    |
+    */
+
+    'previous' => '&laquo; Previous',
+    'next' => 'Next &raquo;',
+
+];