chore: setup PHPStan for project tooling

.gitignore

 
 tools/
+
+phpstan.neon

.phive/phars.xml

 <?xml version="1.0" encoding="UTF-8"?>
 <phive xmlns="https://phar.io/phive">
-  <phar name="phpstan" version="^1.10.67" installed="1.10.67" location="./tools/phpstan" copy="false"/>
+  <phar name="phpstan" version="1.11.1" installed="1.11.1" location="./tools/phpstan" copy="false"/>
 </phive>

tools/phpstan

-/home/hen/.phive/phars/phpstan-1.10.67.phar
\ No newline at end of file
+/Users/jan/.phive/phars/phpstan-1.11.1.phar
\ No newline at end of file