Update dependency StackExchange.Redis to 2.8.31

Author: renovate[bot]

Difficalcy/Difficalcy.csproj

@@ -10,7 +10,7 @@
 
   <ItemGroup>
     <PackageReference Include="Swashbuckle.AspNetCore" Version="7.3.1" />
-    <PackageReference Include="StackExchange.Redis" Version="2.8.24" />
+    <PackageReference Include="StackExchange.Redis" Version="2.8.31" />
   </ItemGroup>
 
 </Project>