Update or extend to PHPStan 2.x

[alexgit2k]

Last November PHPStan 2 has been released which is about 3 times faster (https://phpstan.org/blog/phpstan-2-0-released-level-10-elephpants).

craftcms/phpstan allows only 1.4.6 to 1.9.9, but not 2:

phpstan/composer.json

Line 5 in b61bba1

"phpstan/phpstan": "^1.4.6"

So this should be updated or extended to also use version 2:

"package/name": "^1.4.6 || ^2.0"