Bump Discord.Net from 2.3.0 to 2.3.1

Bumps [Discord.Net](https://github.com/RogueException/Discord.Net) from 2.3.0 to 2.3.1.
- [Release notes](https://github.com/RogueException/Discord.Net/releases)
- [Changelog](https://github.com/discord-net/Discord.Net/blob/dev/CHANGELOG.md)
- [Commits](discord-net/Discord.Net@2.3.0...2.3.1)

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

GrammarNazi.App/GrammarNazi.App.csproj

@@ -6,7 +6,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Discord.Net" Version="2.3.0" />
+    <PackageReference Include="Discord.Net" Version="2.3.1" />
     <PackageReference Include="FirebaseAuthentication.net" Version="3.6.0" />
     <PackageReference Include="FirebaseDatabase.net" Version="4.0.6" />
     <PackageReference Include="Microsoft.VisualStudio.Azure.Containers.Tools.Targets" Version="1.10.8" />

GrammarNazi.Core/GrammarNazi.Core.csproj

@@ -5,7 +5,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Discord.Net" Version="2.3.0" />
+    <PackageReference Include="Discord.Net" Version="2.3.1" />
     <PackageReference Include="FirebaseDatabase.net" Version="4.0.6" />
     <PackageReference Include="Markdig" Version="0.23.0" />
     <PackageReference Include="Microsoft.EntityFrameworkCore" Version="5.0.4" />

GrammarNazi.Domain/GrammarNazi.Domain.csproj

@@ -6,7 +6,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Discord.Net" Version="2.3.0" />
+    <PackageReference Include="Discord.Net" Version="2.3.1" />
     <PackageReference Include="Newtonsoft.Json" Version="12.0.3" />
     <PackageReference Include="Telegram.Bot" Version="15.7.1" />
   </ItemGroup>