Update dependency ReactiveUI.Avalonia to 11.4.3

Author: renovate[bot]

src/AnimationRx.Avalonia/AnimationRx.Avalonia.csproj

@@ -9,7 +9,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="ReactiveUI.Avalonia" Version="11.3.8" />
+    <PackageReference Include="ReactiveUI.Avalonia" Version="11.4.3" />
   </ItemGroup>
 
 </Project>