Bump ImageSharp to 3.1.5

https://github.com/advisories/GHSA-63p8-c4ww-9cg7

src/Directory.Packages.props

@@ -44,7 +44,7 @@
     <PackageVersion Include="Selenium.WebDriver.ChromeDriver" Version="91.0.4472.10100" />
     <PackageVersion Include="Sentry" Version="3.31.0" />
     <PackageVersion Include="SharpZipLib" Version="1.4.2" />
-    <PackageVersion Include="SixLabors.ImageSharp" Version="3.1.4" />
+    <PackageVersion Include="SixLabors.ImageSharp" Version="3.1.5" />
     <PackageVersion Include="StyleCop.Analyzers" Version="1.1.118" />
     <PackageVersion Include="Swashbuckle.AspNetCore.Annotations" Version="6.6.2" />
     <PackageVersion Include="Swashbuckle.AspNetCore.SwaggerGen" Version="6.6.2" />