composer(deps-dev): Bump phpunit/phpunit from 9.5.25 to 9.5.26

Bumps [phpunit/phpunit](https://github.com/sebastianbergmann/phpunit) from 9.5.25 to 9.5.26.
- [Release notes](https://github.com/sebastianbergmann/phpunit/releases)
- [Changelog](https://github.com/sebastianbergmann/phpunit/blob/main/ChangeLog-9.5.md)
- [Commits](sebastianbergmann/phpunit@9.5.25...9.5.26)

---
updated-dependencies:
- dependency-name: phpunit/phpunit
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

composer.json

@@ -26,7 +26,7 @@
     "ergebnis/composer-normalize": "^2.28.3",
     "ergebnis/license": "^2.0.0",
     "ergebnis/php-cs-fixer-config": "^4.10.0",
-    "phpunit/phpunit": "^9.5.25",
+    "phpunit/phpunit": "^9.5.26",
     "psalm/plugin-phpunit": "~0.17.0",
     "vimeo/psalm": "^4.29"
   },