Bump com.adyen:adyen-java-api-library in /giving-example (#235)

Bumps [com.adyen:adyen-java-api-library](https://github.com/adyen/adyen-java-api-library) from 28.3.1 to 28.4.0.
- [Release notes](https://github.com/adyen/adyen-java-api-library/releases)
- [Commits](Adyen/adyen-java-api-library@v28.3.1...v28.4.0)

---
updated-dependencies:
- dependency-name: com.adyen:adyen-java-api-library
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Upgrade Adyen Java library v28.3.1 (#234)

Webhook processing: 202 response with empty body (#198)

* Refactor webhook accept

* Import HttpStatus