build: ugrade PHPStan to v2.0

Additionally bumped the Psalm package version to the latest installed
one.

Signed-off-by: Sacha Telgenhof <me@sachatelgenhof.com>

composer.json

@@ -43,9 +43,10 @@
     "azuyalabs/php-cs-fixer-config": "^0.3",
     "mikey179/vfsstream": "^1.6",
     "phan/phan": "^5.4",
-    "phpstan/phpstan": "^1.10",
+    "phpstan/phpstan": "^2.0",
+    "phpstan/phpstan-deprecation-rules": "^2.0",
     "phpunit/phpunit": "^8.5 || ^9.6",
-    "vimeo/psalm": "^5.20"
+    "vimeo/psalm": "^5.26"
   },
   "suggest": {
     "ext-calendar": "For calculating the date of Easter"