minor #54278 [ErrorHandler] Skip failing tests when "xdebug.file_link_format" option is defined (lyrixx)

This PR was submitted for the 7.1 branch but it was merged into the 6.4 branch instead.

Discussion
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[ErrorHandler] Skip failing tests when "xdebug.file_link_format" option is defined

| Q             | A
| ------------- | ---
| Branch?       | 6.4
| Bug fix?      | no
| New feature?  | no
| Deprecations? | no
| Issues        |
| License       | MIT

This test annoys me since ... many years!
So let's skip it.

Commits
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05ad85d229 [ErrorHandler] Skip failing tests when "xdebug.file_link_format" option is defined

Author: nicolas-grekas

Tests/ErrorRenderer/FileLinkFormatterTest.php

@@ -27,6 +27,11 @@ public function testWhenNoFileLinkFormatAndNoRequest()
 
     public function testAfterUnserialize()
     {
+        if (get_cfg_var('xdebug.file_link_format')) {
+            // There is no way to override "xdebug.file_link_format" option in a test.
+            $this->markTestSkipped('php.ini has a custom option for "xdebug.file_link_format".');
+        }
+
         $ide = $_ENV['SYMFONY_IDE'] ?? $_SERVER['SYMFONY_IDE'] ?? null;
         $_ENV['SYMFONY_IDE'] = $_SERVER['SYMFONY_IDE'] = null;
         $sut = unserialize(serialize(new FileLinkFormatter()));