version specifier arg not working for libc

[mjlbach]

Checks

• I have checked that this issue has not already been reported.

• I have confirmed this bug exists on the latest version of pixi, using pixi --version.

Reproducible example

The following pixi.toml

[project]
name = "pixi-open3d"
version = "0.1.0"
description = "Pixi Open3d"
authors = ["Michael Lingelbach"]
channels = [ "conda-forge" ]
platforms = ["linux-64"]

[tasks]

[dependencies]
python = "~=3.10.0"

[pypi-dependencies]
open3d = "*"

[system-requirements]
libc = { family = "glibc", version = "2.27" }

causes

❯ pixi install
 WARN pixi::project: ALPHA feature enabled!

It looks like your project contains `[pypi-dependencies]`. This feature is currently still in an ALPHA state!

You may encounter bugs or weird behavior. Please report any and all issues you encounter on our github repository:

        https://github.com/prefix-dev/pixi.

  × The following packages are incompatible
  │ |-- open3d * cannot be installed because there are no viable options:
  │     |-- open3d 0.17.0 is excluded because none of the artifacts are compatible with the Python interpreter or glibc version
  │     |-- open3d 0.16.1 is excluded because none of the artifacts are compatible with the Python interpreter or glibc version
  │     |-- open3d 0.16.0 is excluded because none of the artifacts are compatible with the Python interpreter or glibc version
  │     |-- open3d 0.15.2 is excluded because none of the artifacts are compatible with the Python interpreter or glibc version
  │     |-- open3d 0.15.1 is excluded because none of the artifacts are compatible with the Python interpreter or glibc version
  │     |-- open3d 0.14.1 is excluded because none of the artifacts are compatible with the Python interpreter or glibc version
  │     |-- open3d 0.13.0 is excluded because none of the artifacts are compatible with the Python interpreter or glibc version
  │     |-- open3d 0.12.0 is excluded because none of the artifacts are compatible with the Python interpreter or glibc version
  │     |-- open3d 0.11.2 is excluded because none of the artifacts are compatible with the Python interpreter or glibc version
  │     |-- open3d 0.11.1 is excluded because none of the artifacts are compatible with the Python interpreter or glibc version
  │     |-- open3d 0.11.0 is excluded because none of the artifacts are compatible with the Python interpreter or glibc version
  │     |-- open3d 0.10.0.1 is excluded because none of the artifacts are compatible with the Python interpreter or glibc version
  │     |-- open3d 0.10.0.0 is excluded because none of the artifacts are compatible with the Python interpreter or glibc version
  │     |-- open3d 0.9.0.0 is excluded because none of the artifacts are compatible with the Python interpreter or glibc version
  │     |-- open3d 0.8.0.0 is excluded because none of the artifacts are compatible with the Python interpreter or glibc version

However, the following pixi.toml works fine:

[project]
name = "pixi-open3d"
version = "0.1.0"
description = "Pixi Open3d"
authors = ["Michael Lingelbach"]
channels = [ "conda-forge" ]
platforms = ["linux-64"]

[tasks]

[dependencies]
python = "~=3.10.0"

[pypi-dependencies]
open3d = "*"

[system-requirements]
libc = "2.27" 

Issue description

See above

Expected behavior

See above