Add support for loongarch64 on linux

[xflcx1991]

Problem description

I noticed that PR #4163 claims to support loongarch64 architecture. In actual testing on the machine, it can indeed compile the binary, but the 'pixi init' command throws an error and fails to recognize the "linux-loong64" environment.

(ssh)studentmain@a-loong-loooooong-ago [ test ] ! pixi init
✔ Created /home/studentmain/test/pixi.toml
Error:   × Expected one of 'linux-32', 'linux-64', 'linux-aarch64', 'linux-armv6l', 'linux-armv7l', 'linux-ppc64le', 'linux-ppc64', 'linux-s390x', 'linux-riscv32', 'linux-riscv64', 'osx-64',
  │ 'osx-arm64', 'win-32', 'win-64', 'win-arm64', 'emscripten-wasm32', 'wasi-wasm32', 'zos-z'
   ╭─[/home/studentmain/test/pixi.toml:5:15]
 4 │ name = "test"
 5 │ platforms = ["linux-loong64"]
   ·               ─────────────
 6 │ version = "0.1.0"
   ╰────
  help: Did you mean 'linux-64'?

I'm planning to submit a PR to address this issue, but it might take some time. First create an issue to document this requirement.

[ruben-arts]

You are right, feel free to extend the support! I believe it's not too complex. You should start here:

pixi/crates/pixi_manifest/src/toml/platform.rs

Line 13 in 537739c

pub enum TomlPlatform {

As that enum is the input for that error.

[xflcx1991]

You are right, feel free to extend the support! I believe it's not too complex. You should start here:

pixi/crates/pixi_manifest/src/toml/platform.rs

Line 13 in 537739c
pub enum TomlPlatform {

As that enum is the input for that error.

Thanks.