chore: add PHP formatting check

[marandaneto]

💡 Motivation and Context

Add a PHP formatting check to CI so PSR-12 auto-fixable formatting issues are caught before merge.

💚 How did you test it?

• vendor/bin/phpcs --standard=phpcs.xml test/FeatureFlagEvaluationsTest.php
• actionlint .github/workflows/php.yml
• git diff --check

📝 Checklist

• I reviewed the submitted code.
• I added tests to verify the changes.
• I updated the docs if needed.
• No breaking change or entry added to the changelog.

If releasing new changes

• Ran pnpm changeset to generate a changeset file

[greptile-apps]

Prompt To Fix All With AI

Fix the following 1 code review issue. Work through them one at a time, proposing concise fixes.

---

### Issue 1 of 1
.github/workflows/php.yml:102
The `--report=summary` flag is a `phpcs` option and is not supported by `phpcbf`. PHP_CodeSniffer prints a "NOTE: The --report and --report-file options are not supported by PHPCBF." message at runtime and ignores it, so the step still works, but the flag is superfluous and can confuse readers into thinking it controls `phpcbf`'s output format.

```suggestion
          php phpcbf.phar --standard=phpcs.xml --no-colors || phpcbf_status=$?
```

_{Reviews (1): Last reviewed commit: "chore: add PHP formatting check" | Re-trigger Greptile}