Build(deps): Bump MongoDB.Driver from 2.19.0 to 2.28.0

Bumps MongoDB.Driver from 2.19.0 to 2.28.0.

---
updated-dependencies:
- dependency-name: MongoDB.Driver
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

src/Bot/Bot.csproj

@@ -13,6 +13,7 @@
     </ItemGroup>
 
     <ItemGroup>
+        <PackageReference Include="MongoDB.Driver" Version="2.28.0" />
         <PackageReference Include="Serilog" Version="4.0.1" />
         <PackageReference Include="Serilog.AspNetCore" Version="8.0.2" />
         <PackageReference Include="Serilog.Enrichers.AssemblyName" Version="2.0.0" />