Update required cs-fixer version

`fully_qualified_strict_types` => `leading_backslash_in_global_namespace` we want to use was only introduced with 3.46 PHP-CS-Fixer/PHP-CS-Fixer@0061223

Signed-off-by: Joas Schilling <213943+nickvergessen@users.noreply.github.com>

composer.json

@@ -4,7 +4,7 @@
     "type": "library",
     "require": {
         "php": "^7.3|^8.0",
-        "php-cs-fixer/shim": "^3.17"
+        "php-cs-fixer/shim": "^3.46"
     },
     "license": "MIT",
     "authors": [