Correcting command behavior and CI edge cases in uutils coreutils

Problem

Small compatibility and test-infrastructure details can make command behavior harder to verify. In comm, order checking needed to wait until the inputs differ, and the tracking code needed a focused regression test. The env command and CI workflows also had specific option and artifact handling to correct.

Changes

I changed comm to defer its order check until the input files differ, simplified files_differ tracking, and added a check-order test. I also removed the --file extension from env, switched the WASI workflow to the install action for Wasmtime, and made the GNU comment workflow handle a missing comment artifact.

Result

The changes cover command behavior and CI failure cases with targeted updates in the relevant utility and workflows.

Commits: comm tracking and test, defer comm order check, Wasmtime setup, GNU comment artifact, env option