Remove aestheticUpdates Toggle (#5054)

Task/Issue URL: https://app.asana.com/0/488551667048375/1208366976833801/f

### Description
Remove aestheticUpdates Toggle from ExtendedOnboarding feature

### Steps to test this PR _(Optional)_

- [ ] Fresh install from branch
- [ ] Go through all onboarding dialogs
- [ ] Check it works as expected

### No UI changes

Author: nalcalag

app/src/androidTest/java/com/duckduckgo/app/browser/BrowserTabViewModelTest.kt

@@ -516,7 +516,6 @@ class BrowserTabViewModelTest {
         whenever(mockSettingsDataStore.omnibarPosition).thenReturn(TOP)
         whenever(androidBrowserConfig.screenLock()).thenReturn(mockEnabledToggle)
         whenever(mockSSLCertificatesFeature.allowBypass()).thenReturn(mockEnabledToggle)
-        whenever(mockExtendedOnboardingFeatureToggles.aestheticUpdates()).thenReturn(mockEnabledToggle)
         whenever(subscriptions.shouldLaunchPrivacyProForUrl(any())).thenReturn(false)
         whenever(mockDuckDuckGoUrlDetector.isDuckDuckGoUrl(any())).thenReturn(false)
         whenever(mockDuckPlayer.isSimulatedYoutubeNoCookie(any<Uri>())).thenReturn(false)

app/src/main/java/com/duckduckgo/app/onboarding/ui/page/extendedonboarding/ExtendedOnboardingFeatureToggles.kt

@@ -30,9 +30,6 @@ interface ExtendedOnboardingFeatureToggles {
     @Toggle.DefaultValue(false)
     fun self(): Toggle
 
-    @Toggle.DefaultValue(true)
-    fun aestheticUpdates(): Toggle
-
     @Toggle.DefaultValue(false)
     @Experiment
     fun noBrowserCtas(): Toggle