require admins & tz

[nilsnolde]

fixes #4467

this is just a start, unfortunately these changes let all gurka tests fail currently with "no edges near location", very cryptic..

in any case, I wouldn't merge this until just before the next release, it's kinda major for anyone running valhalla.

[nilsnolde]

Do I remember right that we came to the conclusion to host the DBs on Github artifacts instead of baking them into a release? I know there's the risk of broken admin data, but that's what it is then IMO. If someone has a strong need for better coverage, they can do the work to come up with a sane process to achieve that.

Also this move makes admin & tz db's necessary for all tests. While we could technically generate the tz db for windows too, it'd be easier to just download it in CI.

[nilsnolde]

maybe a better route would be: we add a boolean arg to the build process to control whether we require the dbs, which valhalla_build_tiles can set to true. then it's hardly any changes. I don't really like that tests now require them as well.

wdyt?