The Gitea Actions runners are on ARM64 (pi1/pi3) and Go's
ThreadSanitizer fails with 'unsupported VMA range, Found 47 - Supported
48' on those kernels. Race detector is still available locally via
`make test-race`.
This was supposed to land in d63f195 but the prior Write didn't apply.
CI now runs unit + integration tests on every push and PR ; the docker
image is only pushed on main, after tests pass.
