goreleaser: fix bad archive config

[lukasmalkmus]

Had a bad archive config. Fixed it and also changed CI to run goreleaser --snapshot to mitigate this in the future.

Also includes a fix for #290.

[lukasmalkmus]

Fixed the CI failures! 🎉

The issue was that the workflow changed from goreleaser build --snapshot to goreleaser --snapshot, which creates archives instead of raw binaries. The test jobs were looking for raw binaries at paths like dist/linux_linux_amd64_v1/axiom, but those didn't exist anymore.

The fix updates the test jobs to:

1. Upload the archives created by goreleaser --snapshot (e.g., dist/axiom_*_linux_amd64.tar.gz)
2. Extract the binaries from these archives before testing
3. Handle the different archive formats (tar.gz for Unix, zip for Windows)

The CI should now pass with the goreleaser running in full snapshot mode, which will help catch release issues early as intended.