Workspace maintenance (#1884)

Changes:
- Add missing crate to the workspace
- Remove versions from local dependency links

Maybe it is finally worth it to add this scrip to the CI to find these
things earlier:
[check-deps.py](https://github.com/ggwpez/substrate-scripts/blob/master/import-runtime-repos/check-deps.py).

@paritytech/ci what would be the best location for that check?  
It takes only a second to run, so maybe we can squeeze it into one of
the existing checks?
Otherwise creating a new GH workflow feels a bit wasteful... maybe i can
group it with https://github.com/paritytech/polkadot-sdk/pull/1831

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Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>