vendor: github.com/moby/buildkit v0.21.0-rc1

Signed-off-by: Jonathan A. Sternberg <jonathan.sternberg@docker.com>

vendor/github.com/moby/sys/user/idtools_windows.go

@@ -0,0 +1,13 @@
+package user
+
+import (
+	"os"
+)
+
+// This is currently a wrapper around [os.MkdirAll] since currently
+// permissions aren't set through this path, the identity isn't utilized.
+// Ownership is handled elsewhere, but in the future could be support here
+// too.
+func mkdirAs(path string, _ os.FileMode, _, _ int, _, _ bool) error {
+	return os.MkdirAll(path, 0)
+}