Bump Npgsql from 4.0.3 to 4.1.9 (#2799)

Author: dependabot[bot]

src/NHibernate.Test/NHibernate.Test.csproj

@@ -64,7 +64,7 @@
     <PackageReference Include="NUnit3TestAdapter" Version="3.15.1" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.10.0" />
     <PackageReference Include="FirebirdSql.Data.FirebirdClient" Version="6.6.0" />
-    <PackageReference Include="Npgsql" Version="4.0.3" />
+    <PackageReference Include="Npgsql" Version="4.1.9" />
     <PackageReference Include="MySql.Data" Version="8.0.25" />
   </ItemGroup>
   <ItemGroup Condition="$(NhNetFx)">