fix: scope the action identity to the step executing an action (#1359)

`github.action_repository`/`github.action_ref` and their env vars now belong to the step executing an action, like on GitHub: set for remote actions, empty for `run`, `docker://` and local steps. Before, a local action nested in a remote composite resolved `$/` against the remote action instead of the workflow's repository.

Updates actionslib to v1.5.1, which accepts `$/` as the repository root action.

Co-authored-by: bircni <[email protected]>
Reviewed-on: https://gitea.com/gitea/runner/pulls/1359
Reviewed-by: bircni <[email protected]>
Co-authored-by: silverwind <[email protected]>

act/runner/step_action_builtin.go

@@ -39,7 +39,7 @@ func (sab *stepActionBuiltin) main() common.Executor {
 		rc.ApplyExtraPath(ctx, &sab.env)
 		return sab.run(ctx, &action.Context{
 			Container:       rc.JobContainer,
-			Github:          rc.getGithubContext(ctx),
+			Github:          getStepGithubContext(ctx, sab),
 			Inputs:          sab.Step.With,
 			HostWorkdir:     rc.Config.Workdir,
 			Workspace:       rc.JobContainer.ToContainerPath(rc.Config.Workdir),
@@ -58,10 +58,6 @@ func (sab *stepActionBuiltin) post() common.Executor { return common.NewPipeline
 
 func (sab *stepActionBuiltin) getRunContext() *RunContext { return sab.RunContext }
 
-func (sab *stepActionBuiltin) getGithubContext(ctx context.Context) *model.GithubContext {
-	return sab.RunContext.getGithubContext(ctx)
-}
-
 func (sab *stepActionBuiltin) getStepModel() *model.Step { return sab.Step }
 
 func (sab *stepActionBuiltin) getEnv() *map[string]string { return &sab.env }