Bump OPCFoundation.NetStandard.Opc.Ua in /UaClient.UnitTests

Bumps [OPCFoundation.NetStandard.Opc.Ua](https://github.com/OPCFoundation/UA-.NETStandard) from 1.4.371.50 to 1.5.374.54.
- [Release notes](https://github.com/OPCFoundation/UA-.NETStandard/releases)
- [Commits](OPCFoundation/UA-.NETStandard@1.4.371.50...1.5.374.54)

---
updated-dependencies:
- dependency-name: OPCFoundation.NetStandard.Opc.Ua
  dependency-type: direct:production
...

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

UaClient.UnitTests/Workstation.UaClient.UnitTests.csproj

@@ -31,7 +31,7 @@
     <PackageReference Include="Microsoft.Extensions.Logging" Version="7.0.0" />
     <PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="7.0.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.4.1" />
-    <PackageReference Include="OPCFoundation.NetStandard.Opc.Ua" Version="1.4.371.50" />
+    <PackageReference Include="OPCFoundation.NetStandard.Opc.Ua" Version="1.5.374.54" />
     <PackageReference Include="xunit" Version="2.4.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5">
       <PrivateAssets>all</PrivateAssets>