feat: allow proxyProvider outpost field to be updated

pkg/controllers/proxyprovider/controller_test.go

@@ -123,6 +123,7 @@ func TestController_syncHandler_update(t *testing.T) {
 	pp.Status.PK = "42"
 	pp.Finalizers = []string{DeleteAuthentikProxyProviderFinalizer}
 
+	var outpostPartialUpdateCalled bool
 	server := newAuthentikTestServer(t, authentikTestHandlers{
 		allRetrieve: func(w http.ResponseWriter, _ *http.Request) {
 			writeJSON(t, w, http.StatusOK, map[string]any{"pk": 42})
@@ -130,6 +131,20 @@ func TestController_syncHandler_update(t *testing.T) {
 		proxyPartialUpdate: func(w http.ResponseWriter, _ *http.Request) {
 			writeJSON(t, w, http.StatusOK, map[string]any{"pk": 42})
 		},
+		outpostRetrieve: outpostRetrieveHandler(t, nil),
+		outpostPartialUpdate: func(w http.ResponseWriter, r *http.Request) {
+			outpostPartialUpdateCalled = true
+			var body struct {
+				Providers []int32 `json:"providers"`
+			}
+			if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+				t.Fatalf("decode outpost patch body: %v", err)
+			}
+			if !slices.Contains(body.Providers, 42) {
+				t.Fatalf("patched providers = %v, want to contain 42", body.Providers)
+			}
+			writeJSON(t, w, http.StatusOK, map[string]any{"pk": testOutpostID, "providers": body.Providers})
+		},
 	})
 	t.Cleanup(server.Close)
 
@@ -140,6 +155,9 @@ func TestController_syncHandler_update(t *testing.T) {
 	if err != nil {
 		t.Fatalf("syncHandler() error = %v", err)
 	}
+	if !outpostPartialUpdateCalled {
+		t.Fatal("expected Authentik outpost partial update call")
+	}
 
 	got := getProxyProvider(t, ctrl, pp.Namespace, pp.Name)
 	if got.Status.PK != "42" {