[Feature request] Explicit dry-run cli option

[birdhackor]

If I want to know which packages versions will change when I do a upgradable relock, I might want to do the following command

$ uv lock -U --dry-run

Currently, there seems to be no direct instruction to achieve a similar effect. The following command will report an error and cannot achieve the effect I want.

$ uv lock -U --locked
Resolved 10 packages in 126ms
error: The lockfile at `uv.lock` needs to be updated, but `--locked` was provided. To update the lockfile, run `uv lock`.

[charliermarsh]

This makes sense to me.

[zanieb]

Makes sense. There's also uv lock -U && git diff && git reset --hard, but we can do better.

[charliermarsh]

Closed by #7783.