Update dependency Duende.IdentityServer to 7.4.0

Author: xdev-renovate

src/OpenIdConnectServerMock.csproj

@@ -26,7 +26,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Duende.IdentityServer" Version="7.3.2" />
+    <PackageReference Include="Duende.IdentityServer" Version="7.4.0" />
     <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="8.0.21" />
     <PackageReference Include="Microsoft.Extensions.FileProviders.Embedded" Version="8.0.21" />
     <PackageReference Include="Serilog.AspNetCore" Version="8.0.3" />