feat: Allow building without docker support (#1507)

* feat: Allow building without docker support

* fix macos build tag

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

act/container/docker_stub.go

@@ -0,0 +1,57 @@
+//go:build WITHOUT_DOCKER || !(linux || darwin || windows)
+
+package container
+
+import (
+	"context"
+	"runtime"
+
+	"github.com/docker/docker/api/types"
+	"github.com/nektos/act/pkg/common"
+	"github.com/pkg/errors"
+)
+
+// ImageExistsLocally returns a boolean indicating if an image with the
+// requested name, tag and architecture exists in the local docker image store
+func ImageExistsLocally(ctx context.Context, imageName string, platform string) (bool, error) {
+	return false, errors.New("Unsupported Operation")
+}
+
+// RemoveImage removes image from local store, the function is used to run different
+// container image architectures
+func RemoveImage(ctx context.Context, imageName string, force bool, pruneChildren bool) (bool, error) {
+	return false, errors.New("Unsupported Operation")
+}
+
+// NewDockerBuildExecutor function to create a run executor for the container
+func NewDockerBuildExecutor(input NewDockerBuildExecutorInput) common.Executor {
+	return func(ctx context.Context) error {
+		return errors.New("Unsupported Operation")
+	}
+}
+
+// NewDockerPullExecutor function to create a run executor for the container
+func NewDockerPullExecutor(input NewDockerPullExecutorInput) common.Executor {
+	return func(ctx context.Context) error {
+		return errors.New("Unsupported Operation")
+	}
+}
+
+// NewContainer creates a reference to a container
+func NewContainer(input *NewContainerInput) ExecutionsEnvironment {
+	return nil
+}
+
+func RunnerArch(ctx context.Context) string {
+	return runtime.GOOS
+}
+
+func GetHostInfo(ctx context.Context) (info types.Info, err error) {
+	return types.Info{}, nil
+}
+
+func NewDockerVolumeRemoveExecutor(volume string, force bool) common.Executor {
+	return func(ctx context.Context) error {
+		return nil
+	}
+}