Get rid of some unused dependecies

[flip1995]

changelog: none

[rust-highfive]

r? @Manishearth

(rust-highfive has picked a reviewer for you, use r? to override)

[flip1995]

@bors try

[bors]

⌛ Trying commit 54676e5 with merge 7900993...

[bors]

☀️ Try build successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Build commit: 7900993 (7900993720c2db5e3c159bc0eea16bf2b399fde8)

[Manishearth]

@bors r+

[bors]

📌 Commit 54676e5 has been approved by Manishearth

[bors]

☔ The latest upstream changes (presumably #6907) made this pull request unmergeable. Please resolve the merge conflicts.

[bors]

🔒 Merge conflict

This pull request and the master branch diverged in a way that cannot be automatically merged. Please rebase on top of the latest master branch, and let the reviewer approve again.

How do I rebase?

Assuming self is your fork and upstream is this repository, you can resolve the conflict following these steps:

1. git checkout dep-cleanup (switch to your branch)
2. git fetch upstream master (retrieve the latest master)
3. git rebase upstream/master -p (rebase on top of it)
4. Follow the on-screen instruction to resolve conflicts (check git status if you got lost).
5. git push self dep-cleanup --force-with-lease (update this PR)

You may also read Git Rebasing to Resolve Conflicts by Drew Blessing for a short tutorial.

Please avoid the "Resolve conflicts" button on GitHub. It uses git merge instead of git rebase which makes the PR commit history more difficult to read.

Sometimes step 4 will complete without asking for resolution. This is usually due to difference between how Cargo.lock conflict is handled during merge and rebase. This is normal, and you should still perform step 5 to update this PR.

Error message

Auto-merging clippy_utils/src/lib.rs
CONFLICT (content): Merge conflict in clippy_utils/src/lib.rs
Automatic merge failed; fix conflicts and then commit the result.

[flip1995]

@bors r=Manishearth (just rebased the branch)

[bors]

📌 Commit bdf2dce has been approved by Manishearth

[bors]

⌛ Testing commit bdf2dce with merge 5b3e61d...

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: Manishearth
Pushing 5b3e61d to master...