s3 cache client-side support

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

vendor/github.com/aws/smithy-go/io/reader.go

@@ -0,0 +1,16 @@
+package io
+
+import (
+	"io"
+)
+
+// ReadSeekNopCloser wraps an io.ReadSeeker with an additional Close method
+// that does nothing.
+type ReadSeekNopCloser struct {
+	io.ReadSeeker
+}
+
+// Close does nothing.
+func (ReadSeekNopCloser) Close() error {
+	return nil
+}