Publish the release version of the nuget packages

[thomas-mullaly]

Forgot this argument, so the pack command was trying to pack debug assemblies. This should probably be it for me an PRs on this repo today 😅

To make sure this actually works, I did this locally:

dotnet clean
dotnet build --configuration Release
dotnet pack --no-build src/Ardalis.Result/Ardalis.Result.csproj --configuration Release --output nuget
dotnet pack --no-build src/Ardalis.Result.FluentValidation/Ardalis.Result.FluentValidation.csproj --configuration Release --output nuget
dotnet pack --no-build src/Ardalis.Result.AspNetCore/Ardalis.Result.AspNetCore.csproj --configuration Release --output nuget

and all the pack commands succeeded. apologies for all the CI noise.

[github-actions[bot]]

Package	Line Rate	Branch Rate	Complexity	Health
Ardalis.Result.SampleMinimalApi	69%	100%	2	➖
Ardalis.Result	27%	18%	64	❌
Ardalis.Result.AspNetCore	7%	5%	126	❌
Ardalis.Result.Sample.Core	25%	29%	50	❌
Ardalis.Result.FluentValidation	0%	0%	6	❌
Summary	20% (123 / 620)	11% (16 / 140)	248	❌