Install psalm as dev, sync scripts updates

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

@@ -0,0 +1,24 @@
+<?php
+
+namespace LanguageServerProtocol;
+
+/**
+ * Signature help options.
+ */
+class SignatureHelpOptions
+{
+    /**
+     * The characters that trigger signature help automatically.
+     *
+     * @var string[]|null
+     */
+    public $triggerCharacters;
+
+    /**
+     * @param string[]|null $triggerCharacters
+     */
+    public function __construct(array $triggerCharacters = null)
+    {
+        $this->triggerCharacters = $triggerCharacters;
+    }
+}