This PR restructures the integration tests and prebuilds all common assets used in all tests:
Headscale and Tailscale HEAD image
hi binary that is used to run tests
go cache is warmed up for compilation of the test
This essentially means we spend 6-10 minutes building assets before any tests starts, when that is done, all tests can just sprint through.
It looks like we are saving 3-9 minutes per test, and since we are limited to running max 20 concurrent tests across the repo, that means we had a lot of double work.
There is currently 113 checks, so we have to do five runs of 20, and the saving should be quite noticeable! I think the "worst case" saving would be 20+min and "best case" probably towards an hour.
We are already being punished by github actions, there seem to be
little value in running all the tests for both databases, so only
run a few key tests to check postgres isnt broken.
Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
