Bump phpunit/phpunit from 8.5.52 to 12.5.22 in /_integration/php

Bumps [phpunit/phpunit](https://github.com/sebastianbergmann/phpunit) from 8.5.52 to 12.5.22.
- [Release notes](https://github.com/sebastianbergmann/phpunit/releases)
- [Changelog](https://github.com/sebastianbergmann/phpunit/blob/12.5.22/ChangeLog-12.5.md)
- [Commits](sebastianbergmann/phpunit@8.5.52...12.5.22)

---
updated-dependencies:
- dependency-name: phpunit/phpunit
  dependency-version: 12.5.22
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

_integration/php/composer.json

@@ -7,6 +7,6 @@
         ]
     },
     "require-dev": {
-        "phpunit/phpunit": "^8"
+        "phpunit/phpunit": "^12"
     }
 }