Bump http from 0.12.2 to 0.13.4 in /reports/dart

Bumps [http](https://github.com/dart-lang/http/tree/master/pkgs) from 0.12.2 to 0.13.4.
- [Release notes](https://github.com/dart-lang/http/releases)
- [Commits](https://github.com/dart-lang/http/commits/0.13.4/pkgs)

---
updated-dependencies:
- dependency-name: http
  dependency-type: indirect
...

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