[NWD] Update SixLabors.ImageSharp version

Bug: b/335372123
Bug: b/335372162
Change-Id: Ife8ad72293f6ecd56d24108fbe6dd5e181113454
Reviewed-on: https://gnocchi-internal-review.git.corp.google.com/c/third_party/epplus/+/200380
Reviewed-by: Adam Stevens <adamws@google.com>

EPPlus/EPPlusSDK.csproj

diff --git a/EPPlus/EPPlusSDK.csproj b/EPPlus/EPPlusSDK.csproj
index 1b63cf3..09bc049 100644
--- a/EPPlus/EPPlusSDK.csproj
+++ b/EPPlus/EPPlusSDK.csproj
@@ -16,6 +16,7 @@
   <ItemGroup>
     <PackageReference Include="IronSoftware.System.Drawing" Version="2024.3.4" />
     <PackageReference Include="Microsoft.CSharp" Version="4.7.0" />
+    <PackageReference Include="SixLabors.ImageSharp" Version="3.1.4" />  <!--Do not remove - b/335372123 and others-->
     <PackageReference Include="System.CodeDom" Version="5.0.0" />
     <PackageReference Include="System.Drawing.Common" Version="6.0.0" />
     <PackageReference Include="System.Security.Cryptography.Pkcs" Version="5.0.1" />