Bump Npgsql from 4.1.9 to 6.0.5

Bumps [Npgsql](https://github.com/npgsql/npgsql) from 4.1.9 to 6.0.5.
- [Release notes](https://github.com/npgsql/npgsql/releases)
- [Commits](npgsql/npgsql@v4.1.9...v6.0.5)

---
updated-dependencies:
- dependency-name: Npgsql
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

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="8.5.2" />
-    <PackageReference Include="Npgsql" Version="4.1.9" />
+    <PackageReference Include="Npgsql" Version="6.0.5" />
     <PackageReference Include="MySql.Data" Version="8.0.26" />
   </ItemGroup>
   <ItemGroup Condition="$(NhNetFx)">