feature/featuretags, Makefile: fix bug with CLI build tag and depaware, add variant

When I added dependency support to featuretag, I broke the handling of
the non-omit build tags (as used by the "box" support for bundling the
CLI into tailscaled). That then affected depaware. The
depaware-minbox.txt this whole time recently has not included the CLI.

So fix that, and also add a new depaware variant that's only the
daemon, without the CLI.

Updates #12614
Updates #17139

Change-Id: I4a4591942aa8c66ad8e3242052e3d9baa42902ca
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

feature/featuretags/featuretags.go

@@ -40,9 +40,6 @@ func Requires(ft FeatureTag) set.Set[FeatureTag] {
 	s := set.Set[FeatureTag]{}
 	var add func(FeatureTag)
 	add = func(ft FeatureTag) {
-		if !ft.IsOmittable() {
-			return
-		}
 		s.Add(ft)
 		for _, dep := range Features[ft].Deps {
 			add(dep)

feature/featuretags/featuretags_test.go

@@ -36,6 +36,10 @@ func TestRequires(t *testing.T) {
 			in:   "drive",
 			want: setOf("drive"),
 		},
+		{
+			in:   "cli",
+			want: setOf("cli"),
+		},
 		{
 			in:   "serve",
 			want: setOf("serve", "netstack"),