build(deps): bump flow-php/etl-adapter-http in /web/landing

Bumps [flow-php/etl-adapter-http](https://github.com/flow-php/etl-adapter-http) from 0.27.0 to 0.28.0.
- [Commits](flow-php/etl-adapter-http@0.27.0...0.28.0)

---
updated-dependencies:
- dependency-name: flow-php/etl-adapter-http
  dependency-version: 0.28.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]