Bump deps (#1885)

```
* 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/dimchansky/utfbom/.gitignore

@@ -0,0 +1,37 @@
+# Binaries for programs and plugins
+*.exe
+*.dll
+*.so
+*.dylib
+*.o
+*.a
+
+# Folders
+_obj
+_test
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.prof
+
+# Test binary, build with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# Project-local glide cache, RE: https://github.com/Masterminds/glide/issues/736
+.glide/
+
+# Gogland
+.idea/