Remove the vendor directory in .gitignore as these dependencies are needed for php-imap

plugins/php-imap/vendor/illuminate/contracts/Database/Eloquent/Castable.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace Illuminate\Contracts\Database\Eloquent;
+
+interface Castable
+{
+    /**
+     * Get the name of the caster class to use when casting from / to this cast target.
+     *
+     * @param  array  $arguments
+     * @return class-string<CastsAttributes|CastsInboundAttributes>|CastsAttributes|CastsInboundAttributes
+     */
+    public static function castUsing(array $arguments);
+}