[CT-3395] [Feature] Merge --dry-run and --lock into the same flag for dbt deps

[dbeatty10]

Is this your first time submitting a feature request?

• I have read the expectations for open source contributors
• I have searched the existing issues, and I could not find an existing issue for this feature
• I am requesting a straightforward extension of existing dbt functionality, rather than a Big Idea better suited to a discussion

Describe the feature

I don't see the need for both the flags --dry-run and --lock, they could be merged into a same flag as far as I can tell.

Originally posted by @seub in dbt-labs/docs.getdbt.com#4470 (comment)

Describe alternatives you've considered

See dbt-labs/docs.getdbt.com#4470 (comment)_ for context

Who will this benefit?

See dbt-labs/docs.getdbt.com#4470 (comment)_ for context

Are you interested in contributing this feature?

No response

Anything else?

No response

[jtcohen6]

This looks basically right:

dbt-core/core/dbt/task/deps.py

Lines 223 to 225 in 0935570

	# Early return when dry run or lock only.
	if self.args.dry_run or self.args.lock:
	return

The only distinction I can tell is that --dry-run goes along hand-in-hand with --add-package, so like:

dbt deps --lock
dbt deps --add-package --dry-run

In theory (?), the former actually updates the lock file, whereas the latter only updates the package specification file (packages.yml) that would be added if this weren't a "dry run." I don't think this distinction is actually functional in practice. I also don't think it's such an important workflow that we must preserve it and get it working.

I prefer --lock to --dry-run. It feels like a clearer description of what's happening, and it avoids potential confusion with other "dry run" type functionality in dbt, e.g. #8971 or #7839.