Update Psalm to v5.26.1

Author: BenMorel

composer.json

@@ -13,7 +13,7 @@
   "require-dev": {
     "phpunit/phpunit": "^9.0",
     "php-coveralls/php-coveralls": "^2.0",
-    "vimeo/psalm": "5.17.0"
+    "vimeo/psalm": "5.26.1"
   },
   "autoload": {
     "psr-4": {