Relax check_dist_restriction for dry runs

[tgeng]

What's the problem this feature will solve?

I am trying to use pip as a cross platform dependency resolver with the new --report flag. However, currently this does not work well:

$ pip3 install --ignore-installed --python-version 37 --abi cp37m --platform manylinux1_x86_64 --implementation cp --dry-run --quiet --report - frozenlist uwsgi
ERROR: When restricting platform and interpreter constraints using --python-version, --platform, --abi, or --implementation, either --no-deps must be set, or --only-binary=:all: must be set and --no-binary must not be set (or must be set to :none:).

Restricting to --only-binary does not work in this case because uwsgi does not have a compatible wheel.

Describe the solution you'd like

It appears to me that the current check_dist_restriction is unnecessarily restrictive for dry runs. Hence it would be nice to relax this restriction.

Alternative Solutions

It's definitely possible to just use pip functionality as a library and create a separate resolver entry point for my use case. (Or I can just fork pip with my need). But the fix to pip seems simple enough so I would like to try upstream it.

Additional context

#53

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