Install psalm as dev, sync scripts updates

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

@@ -0,0 +1,39 @@
+<?php
+
+namespace LanguageServerProtocol;
+
+/**
+ * An event describing a change to a text document. If range and rangeLength are
+ * omitted the new text is considered to be the full content of the document.
+ */
+class ContentChangeEvent
+{
+    /**
+     * The range of the document that changed.
+     *
+     * @var Range|null
+     */
+    public $range;
+
+    /**
+     * The length of the range that got replaced.
+     *
+     * @var int|null
+     */
+    public $rangeLength;
+
+    /**
+     * The new text of the document.
+     *
+     * @var string
+     */
+    public $text;
+
+    public function __construct(Range $range = null, int $rangeLength = null, string $text = null)
+    {
+        $this->range = $range;
+        $this->rangeLength = $rangeLength;
+        /** @psalm-suppress PossiblyNullPropertyAssignmentValue */
+        $this->text = $text;
+    }
+}