Pixi panics on manifest parsing with environments containing feature "default"

[Hofer-Julian]

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

With the following manifest:

[workspace]
channels = ["conda-forge"]
name = "hello-world"
platforms = ["linux-64", "osx-arm64", "win-64"]

[environments]
test = ["default"]

Running the following command gives

pixi install

thread 'main2' panicked at src/workspace/environment.rs:343:18:
feature usage should have been validated upfront
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
thread 'main' panicked at src/main.rs:54:10:
Tokio executor failed, was there a panic?: Any { .. }

Issue description

With our current setup, pixi cannot deal with environments that explicitly include the "default" feature

Expected behavior

No panic, maybe not even an error.