fix(nfpm): Add extension to produced artifacts (#3940)

Add extension to produced artifacts so that they can be filtered in
later steps

Fixes #3933

Co-authored-by: Carlos A Becker <caarlos0@users.noreply.github.com>

internal/pipe/nfpm/nfpm.go

@@ -443,6 +443,7 @@ func create(ctx *context.Context, fpm config.NFPM, format string, binaries []*ar
 			artifact.ExtraBuilds: binaries,
 			artifact.ExtraID:     fpm.ID,
 			artifact.ExtraFormat: format,
+			artifact.ExtraExt:    format,
 			extraFiles:           contents,
 		},
 	})

internal/pipe/nfpm/nfpm_test.go

@@ -281,6 +281,7 @@ func TestRunPipe(t *testing.T) {
 	for _, pkg := range packages {
 		format := pkg.Format()
 		require.NotEmpty(t, format)
+		require.Equal(t, pkg.Format(), artifact.ExtraOr(*pkg, artifact.ExtraExt, ""))
 		arch := pkg.Goarch
 		if pkg.Goarm != "" {
 			arch += "v" + pkg.Goarm