CI: Re-enable integration tests

[Mossaka]

#9 re-enables make build in the CI, but make test is still failing. Needs more investigation.

[radu-matei]

Is the test running in the container image?
https://github.com/spinkube/containerd-shim-spin/blob/main/Makefile#L6

[Mossaka]

Error: kubectl is not installed
https://github.com/spinkube/containerd-shim-spin/actions/runs/7790247227/job/21245378924?pr=9#step:6:2544

[Mossaka]

Okay, it's strange because https://github.com/spinkube/containerd-shim-spin/actions/runs/7924480883/job/21636104802?pr=14#step:3:8

[kate-goldenring]

@Mossaka can we switch the tests over to using spin registry push rather than docker images? Happy to take a look at fixing the tests

[Mossaka]

Sounds good to me!

[endocrimes]

@kate-goldenring we probably want to have tests that cover both cases (docker build and spin registry push) - so we don't accidentally break them

[jsturtevant]

#35 solved this and we have #37 to track adding tests for spin registry push