Bump Syncfusion.XlsIO.Net.Core from 28.1.38 to 28.2.3 in /src (#844)

Author: dependabot[bot]

src/Directory.Packages.props

@@ -15,7 +15,7 @@
     <PackageVersion Include="Syncfusion.Pdf.Net.Core" Version="28.2.3" />
     <PackageVersion Include="Syncfusion.Presentation.Net.Core" Version="28.1.38" />
     <PackageVersion Include="Syncfusion.PresentationRenderer.Net.Core" Version="28.1.38" />
-    <PackageVersion Include="Syncfusion.XlsIO.Net.Core" Version="28.1.38" />
+    <PackageVersion Include="Syncfusion.XlsIO.Net.Core" Version="28.2.3" />
     <PackageVersion Include="Syncfusion.XlsIORenderer.Net.Core" Version="28.1.38" />
     <PackageVersion Include="Verify" Version="28.9.0" />
     <PackageVersion Include="Verify.DiffPlex" Version="3.1.2" />