tests: add tests for reliable service under packet loss

[ainghazal]

Checklist

• [x] I have read the contribution guidelines
• [x] Iff you changed code related to services, or inter-service communication, make sure you update the diagrams in ARCHITECTURE.md.
• [x] Reference issue for this pull request:

Description

Exercise reliable service passing a vector of packet ID to simulate packet loss.

Additionally, this PR updates github actions version to the latest action release for checkout (v4) and setup-go (v5). Eventually, we'll currently replace the test setup with the one we're using to run tests on the internal packages.

TODO: This PR needs to be rebased on top of #60

[ainghazal]

I think this is ready for review. the only file of interest after merging #60 should be https://github.com/ooni/minivpn/pull/63/files#diff-b9a3711895939a4f4dc918dccb1b8e3eda12d2fea35a79984d7a7a7aab12a9a3 (modulo any minor changes)