Update command-group from 1.0.8 to 2.0.1

With rust-lang#13552 the depencency of on the command-group crate was introduced, which also
introduced a dependency on nix. That version of nix does not build on Haiku. This
change introduces a newer version of command-group, which also updates nix from
0.22.3 to 0.26.1, which is compatible on Haiku.

Author: nielx

Cargo.lock

@@ -17,7 +17,7 @@ rustc-hash = "1.1.0"
 serde = { version = "1.0.137", features = ["derive"] }
 serde_json = "1.0.86"
 jod-thread = "0.1.2"
-command-group = "1.0.8"
+command-group = "2.0.1"
 
 toolchain = { path = "../toolchain", version = "0.0.0" }
 stdx = { path = "../stdx", version = "0.0.0" }