min() and max() do not return false on php8

[staabm]

refs phpstan/phpstan#7239 (comment)

bottom line: in php8 min() and max() do no longer return false
https://www.php.net/manual/en/function.max.php

[staabm]

turned the existing assertions into a php<8 case (minmax-arrays.php)

copied the existing assertion files and adjusted them for php8+ (minmax-php8.php) - meaning turn false into *ERROR*

extracted the assertions which are php version independent into minmax.php

[staabm]

the build error is legit: we no longer trigger the false-positive

Error: Ignored error pattern #^Parameter \#2 \$length of function str_pad expects int, int\<0, max\>\|false given\.$# in path /home/runner/work/phpstan-src/phpstan-src/e2e/integration/repo/src/TextUI/DefaultResultPrinter.php was not matched in reported errors.
 ------ ----------------------------------------------------------------------- 
  Line   src/TextUI/DefaultResultPrinter.php                                    
 ------ ----------------------------------------------------------------------- 
         Ignored error pattern #^Parameter \#2 \$length of function str_pad     
         expects int, int<0, max>\|false given\.$# in path                      
         /home/runner/work/phpstan-src/phpstan-src/e2e/integration/repo/src/Te  
         xtUI/DefaultResultPrinter.php was not matched in reported errors.      
 ------ ----------------------------------------------------------------------- 

in https://github.com/sebastianbergmann/phpunit/blob/93d4bf4c37aec6384bb9e5d390d9049a463a7256/src/TextUI/DefaultResultPrinter.php#L541-L547

[phpstan-bot]

This pull request has been marked as ready for review.

[ondrejmirtes]

Thank you.