Dockerfile: update mvdan/gofumpt to v0.6.0

- full diff: https://github.com/mvdan/gofumpt/compare/v0.4.0...v0.6.0
- v0.6.0 release notes: https://github.com/mvdan/gofumpt/releases/tag/v0.6.0
- v0.5.0 release notes: https://github.com/mvdan/gofumpt/releases/tag/v0.5.0

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Makefile

@@ -52,7 +52,7 @@ shellcheck: ## run shellcheck validation
 .PHONY: fmt
 fmt: ## run gofumpt (if present) or gofmt
 	@if command -v gofumpt > /dev/null; then \
-		gofumpt -w -d -lang=1.19 . ; \
+		gofumpt -w -d -lang=1.21 . ; \
 	else \
 		go list -f {{.Dir}} ./... | xargs gofmt -w -s -d ; \
 	fi

cli/command/image/build/context_test.go

@@ -129,7 +129,6 @@ func TestGetContextFromReaderString(t *testing.T) {
 	tarReader := tar.NewReader(tarArchive)
 
 	_, err = tarReader.Next()
-
 	if err != nil {
 		t.Fatalf("Error when reading tar archive: %s", err)
 	}

cli/command/plugin/create.go

@@ -114,7 +114,6 @@ func runCreate(ctx context.Context, dockerCli command.Cli, options pluginCreateO
 	createCtx, err = archive.TarWithOptions(absContextDir, &archive.TarOptions{
 		Compression: compression,
 	})
-
 	if err != nil {
 		return err
 	}

dockerfiles/Dockerfile.dev

@@ -11,7 +11,7 @@ ENV GOTOOLCHAIN=local
 ENV CGO_ENABLED=0
 
 FROM golang AS gofumpt
-ARG GOFUMPT_VERSION=v0.4.0
+ARG GOFUMPT_VERSION=v0.6.0
 RUN --mount=type=cache,target=/root/.cache/go-build \
     --mount=type=cache,target=/go/pkg/mod \
     --mount=type=tmpfs,target=/go/src/ \