feat: Support graceful job step cancellation (#69)

* for gh-act-runner
* act-cli support as well
* respecting always() and cancelled() of steps
* setup-job, bug report, gh cli and watch wait call is cancelled early

main_test.go

@@ -0,0 +1,11 @@
+package main
+
+import (
+	"os"
+	"testing"
+)
+
+func TestMain(_ *testing.T) {
+	os.Args = []string{"act", "--help"}
+	main()
+}