Bump deps

```
* use go 1.17 semantics in go.mod
* pin tonistiigi/fsutil dep to match docker/docker's dep
go get -u ./...
go mod vendor
```

vendor/github.com/aws/smithy-go/encoding/json/constants.go

@@ -0,0 +1,15 @@
+package json
+
+const (
+	leftBrace  = '{'
+	rightBrace = '}'
+
+	leftBracket  = '['
+	rightBracket = ']'
+
+	comma = ','
+	quote = '"'
+	colon = ':'
+
+	null = "null"
+)