Bump google.golang.org/protobuf from 1.31.0 to 1.33.0 (#20)

Bumps google.golang.org/protobuf from 1.31.0 to 1.33.0.

---
updated-dependencies:
- dependency-name: google.golang.org/protobuf
  dependency-type: indirect
...

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