Update shell completion scripts to use new 'dotnet completions' command.

[tmds]

.NET 10 is introducing a new tab-completion shell integration: https://learn.microsoft.com/en-us/dotnet/core/whats-new/dotnet-10/sdk#native-shell-tab-completion-scripts

This repo has some scripts to setup the completion for different shells: https://github.com/dotnet/sdk/tree/main/scripts

In Fedora/RHEL rpms, these scripts are installed so that shells pick them up. For example, the register-completions.bash gets placed at /usr/share/bash-completion/completions/dotnet.

Probably the scripts should be updated to use dotnet completions instead of dotnet complete.

cc @baronfel @omajid

[baronfel]

I actually think the contents of these scripts should be generated once as part of the RPM packaging process, because the completions command doesn't need to be run on every shell launch for these systems. Run the dotnet completions script bash command once after the binary is built and before packaging to get the latest version and put that in the various necessary locations.

[tmds]

We need to take into account that there is only one /usr/share/bash-completion/completions/dotnet, while there can be multiple .NET SDK versions installed.

dotnet completions depends on the SDK version that is in use. And, for .NET 8/9, there is no dotnet completions.

[tmds]

once after the binary is built and before packaging to get the latest version and put that in the various necessary locations

An alternative may be to have the SDK store the output on the initial invocation, so subsequent invocations can return the cached output.

[marcpopMSFT]

Triage: One option is to just do this with 11 when 8/9 go out of support. The other option is to just follow baronfel's suggestion or do version probing in your setup script. I think we're going to leave this for the maintainers to manage as they suggest.

[tmds]

Suppose I have .NET 10 and .NET 11 SDK installed.
I'm doing some things with the default (latest -> .NET 11) SDK, this should give me NET 11 SDK completions.
When I then cd into a directory that has a global.json that specifies the .NET 10 SDK, I assume I should get .NET 10 SDK completions?
Is that possible? How does it look?