`--upgrade-dependencies` should be marked as deprecated in v2- commands (and a hundred other options as well)

**Describe the bug**

I'm religiously using `--upgrade-dependencies`, but I'm told it's placebo:

> In v2-build, --upgrade-dependencies doesn't do anything, as the build-plan never re-uses existing packages, right?
> It should be an outdated flag...

If so (please verify), it should be marked deprecated, at least in the commandline and web documentation, with an explanation the desired behaviour is now the default.

Edit: let's generalize this task as per @fendor's comment just below.

Start by verifying whether --upgrade-dependencies affects v2-build, then review the command-line and web documentation for other obsolete options as suggested by the generalized scope. Done means the affected options are marked deprecated and explain when the current default provides the desired behavior.

Written by the indexing model from the issue text.