chore(ci): add failOnDeprecation to PHPunit config

[phil-davis]

phpunit on PHP 8.4 and later was reporting a deprecation:

$ composer phpunit
PHPUnit 11.5.56 by Sebastian Bergmann and contributors.

Runtime:       PHP 8.4.24
Configuration: /home/phil/git/sabre-io/xml/tests/phpunit.xml

.....D.........................................................  63 / 116 ( 54%)
.....................................................           116 / 116 (100%)

Time: 00:00.036, Memory: 10.00 MB

1 test triggered 1 PHP deprecation:

1) /home/phil/git/sabre-io/xml/lib/Deserializer/functions.php:361
Calling ReflectionMethod::__construct() with 1 argument is deprecated, use ReflectionMethod::createFromMethodName() instead

Triggered by:

* Sabre\Xml\Deserializer\FunctionCallerTest::testDeserializeFunctionCallerWithDifferentTypesOfCallable
  /home/phil/git/sabre-io/xml/tests/Sabre/Xml/Deserializer/FunctionCallerTest.php:65

OK, but there were issues!
Tests: 116, Assertions: 150, Deprecations: 1.

I think that we may as well get phpunit to fail in this case, and we can easily sort out the needed code change now, rather than waiting until we are forced to do it (when PHP 9 happens, probably)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.45%. Comparing base (782f532) to head (901a903).
⚠️ Report is 4 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master     #344      +/-   ##
============================================
+ Coverage     96.44%   96.45%   +0.01%     
  Complexity      118      118              
============================================
  Files            13       13              
  Lines           478      480       +2     
============================================
+ Hits            461      463       +2     
  Misses           17       17              

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[phil-davis]

Note: Using configuration file /home/runner/work/xml/xml/phpstan.neon.
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 39/39 [▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓] 100%

Error: Call to an undefined static method ReflectionMethod::createFromMethodName().
 ------ ------------------------------------------- 
  Line   lib/Deserializer/functions.php             
 ------ ------------------------------------------- 
  362    Call to an undefined static method         
         ReflectionMethod::createFromMethodName().  
         🪪  staticMethod.notFound                  
 ------ ------------------------------------------- 


 [ERROR] Found 1 error                                                          

Script phpstan analyse handling the phpstan event returned with error code 1

I thought that phpstan was smart enough to realise that code inside an if statement like:

        if (PHP_VERSION_ID >= 80400) {
            $ref = \ReflectionMethod::createFromMethodName($func);
        } else {
            $ref = new \ReflectionMethod($func);
        }

is only for PHP 8.4 and up, and that createFromMethodName exists in those versions.

Looks like I have to work around that.

[staabm]

I opened phpstan/phpstan#15109

We should baseline/ignore the issue for now