Install psalm as dev, sync scripts updates

vendor/felixfbecker/language-server-protocol/src/ReferenceContext.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace LanguageServerProtocol;
+
+class ReferenceContext
+{
+    /**
+     * Include the declaration of the current symbol.
+     *
+     * @var bool
+     */
+    public $includeDeclaration;
+
+    public function __construct(bool $includeDeclaration = null)
+    {
+        /** @psalm-suppress PossiblyNullPropertyAssignmentValue */
+        $this->includeDeclaration = $includeDeclaration;
+    }
+}