feat: Add target sdk for template

[linkdotnet]

This Pull Request does the following additions / changes:

• Added the target SDK as optional parameter when creating the bUnit project
  • It currently targets net6.0 as this is the current LTS. I thought about scripting this away, but it seems way easier to bump our default every 2 years and remove obsolete versions and set the default to the current LTS
• I updated the dependencies to the latest state
• Fixed an issue with h2/h3 in the changelog.md

This tackles partially #1093

[egil]

Nice. I do think the right choice is to make the current latest non-preview the default.

[linkdotnet]

Nice. I do think the right choice is to make the current latest non-preview the default.

Said and done

[linkdotnet]

After playing around a bit - I have to say I am not in favor of having the 3rd party packages updated automatically when someone calls dotnet new bunit for the following reasons:

1. If you don't have internet, we have to define a fallback anyway
2. I, personally, don't like when we do stuff in the post-install script. That remembers me of the npm fiasco. In any case: The user has to trust us even more. Especially, because our post-install scripts might open up a side-channel for other attacks.

[egil]

Ideally, our template would actually do a dotnet new xunit/nunit/mstest followed by a dotnet package add bunit and then a script that make the necessary adjustments to the csproj file. I do not know if that is possible to create.

This way, we do not have to keep our xunit/nunit/mstest templates in sync with the official ones.

The alternative is to basically create our template dynamically at build by creating xunit/nunit/mstest projects, make adjustments, and package all things up into a template.

[linkdotnet]

Yes it is possible:
https://github.com/dotnet/templating/wiki/Post-Action-Registry

We could also add the newly created project to the parent solution

[egil]

We could also add the newly created project to the parent solution

That seems risky, e.g. some repositories also have multiple solution files. Probably leave that to the end user and just do the same as the other test frameworks templates do in that regard.

[egil]

Yes it is possible: https://github.com/dotnet/templating/wiki/Post-Action-Registry

We can look at that in another PR.

[linkdotnet]

That sounds like a plan - at least from my point of view the PR makes the situation to some extent "better".