Speed up integration pipeline

[steeevin88]

i think some caching (amongst other things) can be done to speed up running integration tests in the pipeline added in #110

here's what gemini said maybe they're good recs 😄

Here are a few of the most effective ways to speed this pipeline up:

1. Cache Your Docker Layers
Right now, docker compose up --build is pulling and building everything cold. You can use the actions/cache step in your workflow to save Docker image layers between runs. Next time, it’ll only download what has actually changed.

Pro-tip: If you switch to using Docker Buildx in your action, it has built-in support for GitHub Actions caching (cache-from and cache-to).

2. Use Native GitHub Actions "Service Containers"
Instead of spinning up docker-compose inside a run step, you can define your dependencies (Mongo, Redis) as services directly in your .github/workflows/integration.yml file.

GitHub provisions these natively alongside your runner. It's often much faster and eliminates the overhead of managing docker-compose lifecycle and teardowns yourself.

3. Parallelize the Tests
If the Go integration tests themselves take a while after the containers are up, make sure your tests are designed to run concurrently and use the go test -parallel flag.