feat: initialize scripts of any language with pixi init --script

[Hofer-Julian]

pixi init --script <PATH> picks the block from the file extension (#3751).

• A Python file gets a PEP 723 block; every other known extension gets a conda-script block from a per-language template with the comment prefix, an entrypoint, the toolchain dependency and a hello-world body
• --format gains pep723 and conda-script to override that default
• Unknown extensions error and list the supported ones
• --script names one path, so a workspace directory next to it errors with the combined path to use instead: pixi init --script main.mojo some_directory points at pixi init --script some_directory/main.mojo

[ruben-arts]

I'm not a huge fan of this change. Now we have to make a decision what a file extention is vs a path.

I did like the consistency of --script where every time you do something with a script you add that. I can totally see the --script script.py --format conda-script for this one edge case where you want to use conda-script for python files. And for heavy users we could add a configuration to default to conda-script even for python files for instance.

[Hofer-Julian]

I'm not a huge fan of this change. Now we have to make a decision what a file extention is vs a path.

I did like the consistency of --script where every time you do something with a script you add that. I can totally see the --script script.py --format conda-script for this one edge case where you want to use conda-script for python files. And for heavy users we could add a configuration to default to conda-script even for python files for instance.

As discussed, I don't really agree with your point of view. But I do see where you are coming from, and I can live with the old behavior.