chore(deps): update dependency mudblazor to v9 (#76)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

Directory.Packages.props

@@ -6,7 +6,7 @@
   <!-- Framework-agnostic packages -->
   <ItemGroup>
     <!-- UI Framework packages -->
-    <PackageVersion Include="MudBlazor" Version="8.15.0" />
+    <PackageVersion Include="MudBlazor" Version="9.0.0" />
 
     <!-- Testing packages -->
     <PackageVersion Include="bunit" Version="1.40.0" />