Bump MudBlazor from 6.14.0 to 6.15.0 (#247)

Bumps [MudBlazor](https://github.com/MudBlazor/MudBlazor) from 6.14.0 to 6.15.0.
- [Release notes](https://github.com/MudBlazor/MudBlazor/releases)
- [Changelog](https://github.com/MudBlazor/MudBlazor/blob/dev/CHANGELOG.md)
- [Commits](MudBlazor/MudBlazor@v6.14.0...v6.15.0)

---
updated-dependencies:
- dependency-name: MudBlazor
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Directory.Packages.props

@@ -31,7 +31,7 @@
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
     <PackageVersion Include="Moq" Version="4.20.69" />
     <PackageVersion Include="Moq.AutoMock" Version="3.5.0" />
-    <PackageVersion Include="MudBlazor" Version="6.14.0" />
+    <PackageVersion Include="MudBlazor" Version="6.15.0" />
     <PackageVersion Include="Polly" Version="8.2.1" />
     <PackageVersion Include="Toolbelt.Blazor.PWA.Updater" Version="2.1.0.1" />
     <PackageVersion Include="xunit" Version="2.6.2" />