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/sergi/go-diff/diffmatchpatch/stringutil.go

@@ -9,6 +9,7 @@
 package diffmatchpatch
 
 import (
+	"strconv"
 	"strings"
 	"unicode/utf8"
 )
@@ -86,3 +87,20 @@ func runesIndex(r1, r2 []rune) int {
 	}
 	return -1
 }
+
+func intArrayToString(ns []uint32) string {
+	if len(ns) == 0 {
+		return ""
+	}
+
+	indexSeparator := IndexSeparator[0]
+
+	// Appr. 3 chars per num plus the comma.
+	b := []byte{}
+	for _, n := range ns {
+		b = strconv.AppendInt(b, int64(n), 10)
+		b = append(b, indexSeparator)
+	}
+	b = b[:len(b)-1]
+	return string(b)
+}