Gitea needs the workflow model and the expression evaluator to parse
workflows and to build the task payload this runner consumes, so it had
to depend on gitea.com/gitea/runner for it. Both packages now live in
gitea.dev/actions-proto-go, the module both sides already share, and this
repository consumes them from there.
The GithubContext helpers that need a git checkout on disk (SetRef,
SetSha and SetRepositoryAndOwner) are not moved: they are runner only and
would drag a git client and the act context logger into the shared
module. They become functions of the new act/ghcontext package, together
with their tests.
act/common.CartesianProduct moved to the shared model package as well,
act/model was its only user. act/model/testdata/container-volumes is now
act/runner/testdata/container-volumes, its only user is runner_test.go.
The x-runner-uuid and x-runner-token header names come from
actions-proto-go too, so the runner and Gitea cannot drift apart.
Signed-off-by: Lunny Xiao <xiaolunwen@gmail.com>