[deps] Tools: Update MailKit to 4.16.0 [SECURITY] (#7502)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

src/Core/Core.csproj

@@ -39,7 +39,7 @@
     <PackageReference Include="DnsClient" Version="1.8.0" />
     <PackageReference Include="Fido2.AspNet" Version="3.0.1" />
     <PackageReference Include="Handlebars.Net" Version="2.1.6" />
-    <PackageReference Include="MailKit" Version="4.15.0" />
+    <PackageReference Include="MailKit" Version="4.16.0" />
     <PackageReference Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="8.0.10" />
     <PackageReference Include="Microsoft.Azure.Cosmos" Version="3.52.0" />
     <PackageReference Include="Microsoft.Azure.NotificationHubs" Version="4.2.0" />