Bump SixLabors.ImageSharp in /src/CasCap.Apis.GooglePhotos.Tests

Bumps [SixLabors.ImageSharp](https://github.com/SixLabors/ImageSharp) from 3.1.4 to 3.1.5.
- [Release notes](https://github.com/SixLabors/ImageSharp/releases)
- [Commits](SixLabors/ImageSharp@v3.1.4...v3.1.5)

---
updated-dependencies:
- dependency-name: SixLabors.ImageSharp
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

src/CasCap.Apis.GooglePhotos.Tests/CasCap.Apis.GooglePhotos.Tests.csproj

@@ -11,7 +11,7 @@
     <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="8.0.0" />
     <PackageReference Include="Microsoft.Extensions.Configuration.EnvironmentVariables" Version="8.0.0" />
     <PackageReference Include="Microsoft.Extensions.Configuration.UserSecrets" Version="8.0.0" />
-    <PackageReference Include="SixLabors.ImageSharp" Version="3.1.4" />
+    <PackageReference Include="SixLabors.ImageSharp" Version="3.1.5" />
     <PackageReference Include="xunit" Version="2.7.1" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.5.8">
       <PrivateAssets>all</PrivateAssets>