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

pkg/common/context.go

@@ -0,0 +1,45 @@
+package common
+
+import (
+	"context"
+	"os"
+	"os/signal"
+	"syscall"
+)
+
+func createGracefulJobCancellationContext() (context.Context, func(), chan os.Signal) {
+	ctx := context.Background()
+	ctx, forceCancel := context.WithCancel(ctx)
+	cancelCtx, cancel := context.WithCancel(ctx)
+	ctx = WithJobCancelContext(ctx, cancelCtx)
+
+	// trap Ctrl+C and call cancel on the context
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, os.Interrupt, syscall.SIGTERM)
+	go func() {
+		select {
+		case sig := <-c:
+			if sig == os.Interrupt {
+				cancel()
+				select {
+				case <-c:
+					forceCancel()
+				case <-ctx.Done():
+				}
+			} else {
+				forceCancel()
+			}
+		case <-ctx.Done():
+		}
+	}()
+	return ctx, func() {
+		signal.Stop(c)
+		forceCancel()
+		cancel()
+	}, c
+}
+
+func CreateGracefulJobCancellationContext() (context.Context, func()) {
+	ctx, cancel, _ := createGracefulJobCancellationContext()
+	return ctx, cancel
+}