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

plugins/php-imap/vendor/phar-io/manifest/src/values/RequirementCollection.php

@@ -0,0 +1,40 @@
+<?php declare(strict_types = 1);
+/*
+ * This file is part of PharIo\Manifest.
+ *
+ * Copyright (c) Arne Blankerts <arne@blankerts.de>, Sebastian Heuer <sebastian@phpeople.de>, Sebastian Bergmann <sebastian@phpunit.de> and contributors
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ *
+ */
+namespace PharIo\Manifest;
+
+use Countable;
+use IteratorAggregate;
+use function count;
+
+/** @template-implements IteratorAggregate<int,Requirement> */
+class RequirementCollection implements Countable, IteratorAggregate {
+    /** @var Requirement[] */
+    private $requirements = [];
+
+    public function add(Requirement $requirement): void {
+        $this->requirements[] = $requirement;
+    }
+
+    /**
+     * @return Requirement[]
+     */
+    public function getRequirements(): array {
+        return $this->requirements;
+    }
+
+    public function count(): int {
+        return count($this->requirements);
+    }
+
+    public function getIterator(): RequirementCollectionIterator {
+        return new RequirementCollectionIterator($this);
+    }
+}